The Physical Geography of the Sea and It's Meteorology

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THE PHYSICAL GEOGRAPHY OF THE SEA.

LIEUTENANT

M. F.

MAURY,

LL.D.

i^^^^N-

T.

LONDON: NELSON AND SONS, PATERNOSTER ROW; KI;INBURGH

;

AND NEW YOKK.

&c Digitized by the Internet Archive in

2010 with funding from University of Toronto

http://www.archive.org/details/physicalgeograpOOmaur

miRODUCTIOX TO THE FIRST EDITTOX-1855.

The primary

object of " Tlie

which has grown Sea,

was

Wind and Current

this Treatise

Charts," out of

on the Physical Geography of the

to collect the experience of every navigator as to the

winds

and currents of the ocean, to discuss his observations upon them, and then to present the world with the improvement of commerce and navigation.

By

putting

down on a

same voyage, but

results

chart the tracks of

on charts for the

many

vessels on the

and during

at different times, in different years,

all

and by projecting along each track the winds and currents daily encountered, it was plain that navigators hereafter, by consulting this chart, would have for their guide the results of the combined

seasons,

.experience of all whose tracks were thus pointed out.

Perhaps

it

given port,

might be the

when

his

own

first

voyage of a young navigator to the

personal experience of the winds to be

would

expected, the currents to be encountered by the way,

blank

If so, there

would be the Wind and Current Clwrt.

itself

It

be

wuuld

spread out before him the tracks of a thousand vessels that had pre-

ceded him on the same voyage, wherever at the

same season of the

year.

it

Such a

might

chart,

be,

it

and

was

that, too,

held,

would

show him not only the tracks of the vessels, but the experience also of each master as to the winds and currents by the way, the temperature of the ocean, and the variation of the needle.

All this could

be taken in at a glance, and thus the young mariner, instead of groping his

way

along until the lights of experience should come to

by the slow teachings

of the dearest of

aU

schools,

would here

him find

had already the experience of a thousand navigators guide him on his voyage. He might, therefore, set out upon his

at once that he to

first

voyage with as much confidence in his knowledge as to the winds

and currents he might expect to meet with, as though he himself had already been that

way

a tliDUsand times before.

INTRO DUCTTON TO FIRST EDITION.

IV

Such a chart could not

fail to

masters, and such a chart to sea, they tried

and

it,

with the knowledge

it

commend

itself to intelligent ship-

was constructed

to their surprise

afforded, the

for

They took

them.

and delight they found

it

that,

remote corners of the earth were

many

brought closer together, in some instances by

days'

sail.

passage hence to the equator alone was shortened ten days.

The

Before

commencement of this undertaking, the average passage to Caliwas 183 days but with these charts for their guide, navigators have reduced that average, and brought it down to 1.35 days.

the

fornia

;

Between England and Australia, the average time these charts,

same

going, without

ascertained to be 124 days, and coming, about the

is

making the round voyage one of about 250 days on the These charts, and the system of research to which they

;

average.

have given nearer by

bid fair to bring that colony and the mother country

rise,

many days,—reducing

in

no small measure the average

duration of the round voyage.*

At

the meeting of the British Association of 1853,

member,

a distinguished

meeting in 1854,

its

mated that

this

and embodied describing,

—and

—that in

was

it

stated

by

was again repeated at Bombay, whence he came, it was estithe statement

system of research,

if

extended to the Indian Ocean,

in a set of charts for that sea,

would produce an annual saving

such as I have been

to British

commerce, in

those waters alone, of one or two millions of dollars ;t and in

all seas,

of ten million.s.t *

The outward passage,

average, and the

it

has since been ascertained, has been reduced to 97 days on the

homeward passage has been made

t See Inaugural Address of the Earl of

twenty-fourth meeting.

its

t

.

.

.

"Now

let

us

in 63.

Harrowby, President of the British Association,

make

a calculation of the annual saving to the commerce of the

According to Mr. Maury, the

United States effected by those charts and sailing directions. average freight fi'om the United States to Rio Janeiro tralia.

at

Livei^pool, 1854.

20 cts.; to California, also, about 20

cts.

per ton per day; but (o be within the mark,

we

17.7 cts. per ton per day; to Aus-

is

The mean will

take

of this

it

at 15,

is

a

little

over 19 cents

and include

all

the porta

of South America, China, and the East Indies.

"The

sailing directions

above-named ports "

We

have shortened the passages to California ^0 days,

The mean

to Rio Janeiro 10.

of

of this

South America,

is

20,

Chin;i,

but we

will

take

and the East

it

at 15,

to .\ustralla 20,

and also include the

Indies.

estimate the tonnage of the United States engaged in trade with these places at

1,000,000 tons per

annum.

" With these data, we see that there has been effected a saving

for

each one of theae tons

INTRODUCTION TO FIRST EDITION.

A

system of philosophical research which

and abundant with promise, could not and commend

so rich with fruits

is

to attract the attention

itself to the consideration of the seafaring

of the whole civilized world.

was the

fail

It

experience of

result of the

many

observant men,

and patiently discussed.

brought together for the

first

human knowledge with

its

in attractions to

The

regard to the sea

right-minded men.

results of the first cliart, however,

factory,

was

time,

it

;

now

wonders, and therefore the system of research coidd not be

wanting

The

community

was founded on observation

results tended to increase

and

V

though meagre and unsatis-

were brought to the notice of navigators; their attention

called to the blank sjiaces,

and the importance of more and

ter observations than the old sea-logs generally contained

bet-

was urged

upon them.

They were

told that if each one

would agree

to co-operate in a

general plan of observations at sea, and would send regularly, at the

end of every

an abstract log of their voyage to the National

cruise,

Observatory at Washington, he should, for so doing, be furnished, free of cost,

with a copy of the charts and sailing du-ections that

might be founded upon those observations.

The

quick, practical

mind of the American shipmaster took hold To him the field was inviting, for he

of the proposition at once.

saw

in it the

promise of a rich harvest, and of

So, in a little while, there

many

useful results.

were more than a thousand navigators

engaged day and night, and in

all

parts of the ocean, in

making and

recording observations according to a uniform plan, and in further-

ing this attempt to increase our knowledge as to the winds and ciurents of the sea, and other

phenomena that

relate to its safe navi-

gation and physical geography.

To have

enlist the service of tlie

attention of so

such a large corps of observers, and to

many

clever

and observant men directed

tc

of 15 cents per day for a period of 15 days, whieh will Kive an aggregate of 2,250,000 dollars

saved per annum.

This

is

on

other parts of the world

is

also left out of the calculation.

and

tlie

also the fact that there is a vast

and the United

States,

and

nmonnt"— Extract fi-om

it

will

outward voyage alone, and the tonnage trading with

amount

Take these

all

into consideration,

of foreign tonnage trading between these places

be seen that the annual

sum saved

Hunt's Merchant's Magazine, May, 1S54.

will

sweU

to

an enonnoua

INTEODLXTION TO FIRST EDITION.

VI

the same subject,

was a great point gained

:

it

was a giant

the advancement of knowledge, and a great step toward

stride in

its

spread

upon the waters. Important results soon followed, and great discoveries were made. These attracted the attention of the commercial world, and did not escape the notice of philosophers everywhere.

The

field

was immense, the harvest was

plenteous,

both need and room for more labourers. should gather, or the merest gleaner of of

commerce and navigation

—the

collect,

and there were

Whatever the reapers was to go to the benefit

increase of knowledge

—the good

all.

who

Therefore, all

use the sea were equally interested in the

The Government of the United

undertaking.

States, so considering

the matter, proposed a uniform system of observations at sea, and invited all the maritime states of Christendom to a conference

upon

the subject.

This conference, consisting of representatives from France, England, and Russia, from Sweden and Norway, Holland, Denmark, Belgium, Portugal, and the United States, met in Brussels, August 23, 1853, and recommended a plan of observations which should be followed

on board the vessels of

all

friendly nations,

and

especially of those

there present in the persons of their representatives.

Holy See, the free city of HamBremen and Chili, and the empires of Austria

Prussia, Spain, Sardinia, the

burg, the republics of

and

Brazil, have since offered their co-operation also in the same plan. Thus the sea has been brought regularly within the domains of

philosophical research, and crowded with observers.

In peace and in war these observations are to be carried on in case

;

any of the vessels on board of which they are conducted

be captured, the abstract log observations

is

is

is

of opinion that the results already obtained

to be held sacred.

from this system of research are department of

science,

graphy OF THE

the journal which contains these

—

called

Baron Humboldt

—as

and,

may

Sea.

sufficient to give rise to

which he has If so

called the

much has

by one nation, what may we not expect, lYum the joint co-operation of so many?

a

new

Physical Geo-

already been accomplished

in the course of a

few yeara,

INTRODUCTION TO FIRST EDITION. Rarely before

Vll

there been such a sublime spectacle presented

lias

to the scientific world

:

all

nations agreeing to unite and co-ope-

rate in carrying out one system of philosophical research with regard

Though they may be enemies

to the sea.

in all else, here they are

Every ship that navigates the high

to be friends.

charts and blank abstract logs on board,

seas,

may henceforth

with these be regarded

The instruments

as a floating observatory, a temple of science.

used by every co-operating vessel are to be compared with standards that are

common

to all; so that

anywhere, and in any ship, all

similar observations

by

may be

all

an observation that

other ships in

all

this extensive

admirable system includes will relate only to the

The plan should include the land

made'

parts of the world.

But these meteorological observations which enough.

is

and compared with

referred to

also,

This

sea.

and be

is

and not

universal.

Other great interests of society are to be benefited by such extension

no

less

than commerce and navigation have been.

A

series of sys-

tematic observations, directed over large districts of country, nay, over continents, to the improvement of agricultural and sanitary meteorology, would, I have no doubt, tend to a development of

many The

interesting, important,

agricultural societies

and valuable of

many

results.

states

of

the

Union have

addressed memorials to the American Congress, asking for such extension

;

and

it

is

hoped that that enlightened body

will not fail

favourably to respond.

This plan contemplates the co-operation of

tendom, at least so

far as the form,

all

the states of Chris-

method, subjects of observations,

time of making them, and the interchange of results are concerned.

my

and co-operate The Secretary of the Navy, taking the enlarged and enlightened views which do honour to great statesmen, has officially recommended the adoption of such

I

hope that

in

fellow-citizens will not fail to second

such a humane, wise, and noble scheme.

a system, and the President has asked the favourable consideration Tliese researches for the land look not only to thereof by Congress. the advancement of the great interests of sanitary and agricultural

meteorology, but they involve also a study of the laws which regulate the

atmosphere, and a careful investigation of

Another beautiful feature

in this

system

is,

all its

phenomena.

tJiat it costs

nothing

—

—

INTRODUCTIOX TO FIRST EDITION.

VUl

The instruments that

additional.

these observations at sea call for

are such as are already in use on board of every well-conditioned

and the observations that are required are

ship,

precisely those

which

are necessary for her safe and proper navigation.

Great as

what has been accomplished

the value attached to

is

by these researches,

in the

way

of shortening passages and lessening

the dangers of the sea, a good of higher value

many

is,

in the opinion of

seamen, yet to come, out of the moral, the educational in-

fluence

which

tliey are calculated to exert

A very

munity of the world.

upon the seafaring com-

clever English shipmaster, speaking

recently of the adva,ntages of educational influences

who "

intend to follow the sea, remarks

To the

cultivated lad there

enters on his first voyage.

by

perceive, year

As

a

is

among

those

:

new world spread

out

when he

his education has fitted, so will he

year, that his profession

with things new and instructive.

makes him acquainted

His intelligence will enable him

to appreciate the contrasts of each country, in its general aspect,

manners, and productions, and in modes of navigation adapted to the character of coast, climate, and rivers.

on the phases of the ocean,

terest

breeze,

and

—the

He

will dwell with in-

storm, the calm, and the

will look for traces of the laws

which regulate them.

All this will induce a serious earnestness in his work, and teach to view lightly those irksome

and often

him

offensive duties incident to

the beginner."*

And

that

these

researches

hearted mariners have

have such an

testified.

eS'ect,

many

noble-

Captain Phinney, of the American

ship Gertrude, writing from Callao, January 1855, thus expresses

himself:

" Having to proceed from this to the Chincha Islands, and remain three months,

I avail

myself of the present opportunity to forward to

my two passages over your southern routes, although do so until my own return to the United States next

you abstracts of not required to

•

"The Log

Officers

of a

Merchant

Offlcev,

viewed

witli

and the Youth of the Merchant Semce.

reference to the Education of

By Robert Methren, commander

Young in

tlia

Peninsular and Oiiental Company, and author of the 'NaiTative of the Blenheim Hurricane of 1851."'

London: John Weale, 59

Ackermnn and

Co., Strand.

1851.

Iligli

Ilolboni;

Smith, Elder, and Co., CoruhiU;

INTRODUCTION TO FIEST EDITION. summer, knowing that you are

amply supplied with

less

voyages over these regions than of and, such as

it is,

I

am happy to

ing you with material to

IX

many

contribute

work out

still

abstracts of

other parts of the ocean

my

;

mite toward furnish-

farther toward perfection

your great and glorious task, not only of pointing out the most speedy routes for ships to follow over the ocean, but also of teaching us sailors to look about us, and see by what wonderful manifestations of the

wisdom and goodness of the

great

God we

are continually sur-

rounded. "

For myself,

manded a

I

am

ship, and,

many

free to confess that for

years I com-

although never insensible to the beauties of

nature upon the sea or land, I yet feel that, until I took up your

work, I had been traversing the ocean blindfolded. I did not

know

works of

Him whom

I did not think

the amazing and beautiful combination of

you so beautifully term

'

all

The Great

;

the

First

Thought.' " I feel that, aside from any pecuniary profit to myself from your labours,

you have done me good as a man.

You have

taught

me

to

look above, around, and beneath me, and recognise God's hand in

every element by which I personal benefit.

your work, cause in

in

my

although

am

surrounded.

Your remarks on

me

am

I

grateful for this

this subject, so frequently

feelings

made

of the greatest admiration,

capacity to comprehend your beautiful theory

is

very

limited.

"

The man

letter of this kiud)

fore

spoken as

know how

all

will not be displeased

much

of

might be termed irrelevant matter.

I

I feel,

to excuse, so

what

fail

to

good men, whether ashore or

(in t

have there-

and with sentiments of the greatest

Sentiments like these cannot

from

you express

of such sentiments as

with, or, at least, will

respect."

meet with a hearty response afloat.

Never before has such a corps of observers been enlisted in the cause of any department of physical science as is that which is now about to be engaged in advancing our knowledge of the Pliysical

Geography of the Sea, and never before have men

felt

such an interest

with regard to this knowledge.

Under v.iuds

this

term will be included a philosophical account of the

and currents of the sea

;

of the circulation of the atmosphere

INTRODUCTION TO FIRST EDITION.

X and ocean that

of the temperature

;

hidden in

lie

themselves at the sea and

depths

its

of the wonders and of the phenomena that display ;

In short, I shall treat of the economy of

its surface.

adaptations

its

and depth of the sea

;

—of

waters, its climates, and

its salts, its

and of whatever there may be of general

its

inhabitants,

its

commercial uses or industrial pursuits, for

Physical Geography. The object of this little book, moreover,

all

interest in

such things pertain

to its

and from time

state,

is

to

to time the progress, of this

show the present

new and

beautiful

system of research, as well as of this interesting department of science this

and the aim of the author

;

new

field in

is

may

a manner that

to present the gleanings

from

be interesting and instructive

to all, whether old or young, ashore or afloat, who desire a closer look into " the wonders of the great deep," or a better knowledge as to its winds, its adaptations, or its Physical *

There

is

Geography.*

an old and very rare book which treats upon some of the subjects

this little worli relates:

it is

Description of the Seas."

by Count

L. F. Mai'sigli, a

The copy

to

which

I refer

Frenchman, and

is

called

to

which

"Natural

was translated into Dutch by Boer-

haave, in 1786.

The French count made his observations along the coast of Provence and Languedoc The description only relates to that part of the Mediterranean. The book is divided into four chapters;— the third,

He

first,

on the bottom and shape of the sea; the second, of sea water; the

on the movements of sea water; and the fourth, of sea divides sea water into surface

more than

surface water (not

and deep-sea water

plants.

because,

;

when he makes

salt

from

half a foot below the upper strata), this salt will give a red

colour to blue paper, whereas the salt fiom deep-sea water will not alter the colour at

all.

The reason why

this

The blue paper can only change acid (iodine?)

found

is

its

in surface

colour by the action of an acid.

and not

but he supposes that the saltpetre that

and the motion of the waves, in

the

air, to

be conveyed

earth's cnist, as saltjietre

it

is

is

in deep-sea

water

is, it is

derived from the air;

found in sea water, by the action of the sun's rays

deprived of

its

coarse parts, and, by evaporation, embodied

to beasts or plants for their existence, or deposited

occurs on the plains of Hungary, where the earth absorbs so

upon the

much

of this

vapour.

Donati, also, was a valuable labourer in this to conclude that there are, " at the

field.

His inquiries enabled Mr. Trembley'

bottom of the water, mountains,

plains, valleys,

and

caverns, just as upon the land."

But by

far the

the Mediterranean

most interesting and valuable book touching the physical geography of a Memoir, is Admiral Smyth's List work, entitled "The Mediterranean

Physical, Historical,

*c.

London

:

;

and Nautical. By Kear-Admiral William Henry Smyth,

John W. Parker and '

Son.

1S54.

Philosophical Transactions.

K.S.F., D.C.L.,"

LNTRODUCTION TO THE SIXTH EDITION,

The department of research

Geography of the Sea

of the Physical

there

:

great activity in

is

author of this work to keep

its

it

and

;

it

is

is

a new

up with the improve-

readers posted

made

ments, the developments, and the contributions that are this interesting field

The present

from time

edition contains

field

the aim of the

in

to time.

much that much

has been most carefully revised,

new

is

—

of

;

for the fifth edition

has been recast and

it

some parts omitted.

The

desire

that this

is,

work

shall

keep pace with the progress of

may be supposed, facts are sometimes misinterpreted understood when first developed. Whenever subsequent As

research.

or not

it

research shows such to have been the case, I have not hesitated to tear

down whatever

of conjecture or theory

may have been

built

oa

unstable foundations, and to reconstruct according to the best lights. It

is

proper to say, that, in accounting for the various phenomena

that present themselves, 1

am wedded

to

no theories, and do not

advocate the doctrines of any particular school. Therefore,

when

offered touching

given up the

the explanation which I

any

is

at

my

object.

any time

facts fails to satisfy further developments,

moment one

is

instance that theory

is

system of

old,

preferred which

number of known

it is

suggested which will account for the

new, and equally as well for the

greatest

Tnith

may have

facts.

is

facts.

In every

reconcilable with the

The chapter

of the Gulf Stream

has been enriched with the results of recent investigation, and the theory of the

it

further developed

Open Sea

several others

;

so, also,

that on the Salts of the Sea,

in the Arctic Ocean, the ;

Basin of the Atlantic, and

but these especially have been greatly improved.

INTRODUCTION TO SIXTH EDITION.

Xll

A

separate chapter

is

now devoted

to the

Land and Sea

Breezes,

and extensive contributions have been made to that on Monsoons, Trade Winds, and Cj'clones. has helped I

will,

am

me

Lieutenant Jansen. of the Dutch Navy,

to enrich these with his fine thou^lits.

sure, feel as I do, deeply indebted to

him

The reader for so

much

matter, set forth in his very delightful and pleasing

instructive

manner. National Observatory, WAsniNGrat,

«

Apiil, 1856.

Since the above date, explorations have been

made

in

this

and new veins of precious ore have not yet gone deep enough into

interesting department of science,

We

have been hit upon.

them

to justify a final report.^

In 1849 Congress passed an Act requiring the Secretary of the to employ three small vessels in assisting me to perfect my discoveries. A few weeks ago, Lieiitenant Berryman put to sea

Navy

in

the " Arctic " on this

His attention was especially

duty.

directed to deep-sea soundings along the great telegraphic plateau stretching from

Newfoundland

are of the highest interest.

to

The

Ireland.

Among them

line of volcanic cinders along a line a

is

results, so far,

the discovery of a

thousand miles in length,

and reaching entirely across the Gulf Stream where the submarine telegraph

There

is is

to cross

it.

upon Ozone, upon the cuxulation of the atmo-

also Lieutenant Jansen's experiments

which cast unexpected

light

sphere.

Matter of more general or higher that contained in this fields

new Edition

is

scientific

importance than

seldom gathered from any

of research,

December, 1S5G.

'

Vide subsequent additions in the present Edition, Chapters xxi. xiii.

EXPLANATION OF THE PLATES.

a diagr im to illustrate the circulation of the atmosphere (Chap. the circumference of the circle are belts, and prevailing direction of the wind on each intended to The arrows exterior to the periphery of the circle— section of those belts. which is a section of the earth supposed to be made in the plane of the meridian are intended to show the direction of the upper and lower strata of winds in the general system of atmospherical circulation and also to illustrate how the air brought by each stratum to the calm belts there ascends or descends, as the case may be and then, continuing to flow on, how it crosses over in the direction in which it was travelling when it arrived at the calm zone. Plates II. and III. are drawings of Brooke's Deep-sea Sounding Apparatus, for bringing up specimens of the bottom (g 701). Plate IV. is intended to illustrate the extreme movements of the isotherms The connection be50°, 60°, 70°, &c., in the Atlantic Ocean during the year. tween the law of this motion and the climates of the sea is exceedingly interesting. Plate V. is a section taken from one of the manuscript charts at the Observatory. It illustrates the method adopted there for co-ordinating for the Pilot For this purpose the ocean Charts the winds as reported in the abstract logs. usually five degrees of latitude by five deis divided into convenient sections, These parallelograms are then subdivided into a system of grees of longitude. engraved squares, the months of the year being the ordinates, and the points of As the wind is reported by a vessel that passes the compass being the abscissas. through any part of the parallelogram, so it is assumed to have been at that time From such investigations as this the Pilot Charts all over the parallelogram.

Plate

III.).

is

I.

The arrows and bands within show the calm

—

;

;

—

(§ 929) are constructed. Plate VI. illustrates the position of the

channel of the Gulf Stream (Chap. I.) winter. The diagram A shows a thennometrical profile presented by cross-sections of the Gulf Stream, according to observations made by the The elements for hydrogx-aphieal parties of the United States' Coast Survey. this diagram were kindly furnished me by the superintendent of that work. They are from a paper on the Gulf Stream, read by him before the American Association for the Advancement of Science, at its meeting in Washington, 1854. Imagine a vessel to sail from the Capes of Virginia straight out to sea, crossing the Gulf Stream at right angles, and taking the temperature of its waters at the surface and at various depths. The diagram shows the elevation and depression of the thermometer across this section as they were actually observed by such a for

summer and

vessel.

The black lines x, y, z, in the Gulf Stream, show the course which those Tlie lines a, b, show the computed drift threads of warm waters take (§ 57). route that the unfortunate steamer San Francisco would take after her terrible December 1853. Plate VII. is intended to show how the winds may become

disaster in

geological agents.

It shows where the winds that, in the general system of atmospherical circulation, blow over the deserts and thirsty lands in Asia and Africa (where the

annual amount of precipitation is small) are supposed to get their vapour; and where, as surface winds, they are supposed to condense portions of it whither they are supposed to transport the residue thereof through the upper regions, retaining it until they again become surface winds. Plate VIII. shows the prevailing direction oi' the wind during the year in all ;

EXPLAXATION OF THE PLATES.

XIV

parts of the ocean, as derived from the series of investigations illustrated on Plate YII. It also shows the principal routes across the seas to various places. Where the cross-lines representing the yards are oblique to the keel of the vessel, they indicate that the winds are, for the most part, ahead when perpendicular The figures on or near or square, that the winds are, for the most part, fair. the diagrams representing the vessels, show the average length of the passage in days. The arrows denote the prevailing direction of the wind ; they are supposed to The half-bearded and so that the wind is going as the arrows point. fly u-ith it half-feathered arrows represent monsoons (§ 763), and the stippled or shaded belts the calm zones. In the regions on the polar side of the calms of Capricorn and of Cancer, where the arrows are flying both from the north-west and tlie south-west, the idea intended to be conveyed is, that the prevailing direction of the winds is between the uorth-west and the south-west, and that their frequency is from these two quarters in proportion to the number of arrows. Plate IX. is intended to show the present state of our knowledge with regard to the drift of the ocean, or, more properly, with regard to the great flow of polar and equatorial waters, and their channels of circulation as indicated Ly the thermometer (§ 8S9). Further researches will enable us to imjirove this chart. The most favourite places of resort for the whale—ric/Ai in cold, and sperm in warm water are also exhibited on this chart. Plate X. exhibits the actual path of a storm, which is a type (§ 85) of the West Indian hurricanes. Mr. Redtield, Colonel Eeid, and others, have traced out the paths of a number of such storms. All of this class appear to make for the Gulf Stream after reaching it, they turn about and follow it la their course ;

;

—

:

(S 95).

Mr. Piddington of Calcutta has made the East Indian hurricanes, which are similar to these, the object of special, patient, and laborious investigation. He calls them ci/clones, and has elicited much valuable information concerning them, which may be found embraced in his "Sailor's Horn-huok," "Conversations about Hurricanes," and numerous papers published from time to time in the Journal of the Asiatic Society. Plates XI. and XII. speak for themselves. They are orographic for the North Atlantic Ocean, and exhibit completely the present state of our knowledge with regard to the elevations and depressions in the bed of the sea Plate XII. exhibiting a vertical section of the Atlantic, and showing the contrasts of its bottom with the sea-level in a line from Mexico across Yucatan, Cuba, San Domingo, and the Cape de Verds, to the coast of Africa, marked A on Plate XI. Plate XIII. The data for this Plate are furnished by Maurj''s Storm and Rain Charts, including observations for 107,277 days in the North Atlantic, and 158,025 in the South; collated by Lieutenant J. J. Guthrie, at the Washington Observatory, in 1855. The heavy vertical lines, 5', 10°, 15°, &c., represent parallels of latitude; the other vertical lines, months; and the horizontal lines, per cents., or the number of days in a hundred. The continuous curve line stands for phenomena in the North, and the broken curve line for phenomena in the South Atlantic. Thus the Gales' Curve shows that in every hundred days, and on the average, in the month of January of different years, there have been observed, in the uortheirn hemisjihere, 36 gales (36 per cent.) between the jiarallels of 50° and 55° ; whereas during the same time and between the same parallels in the southern hemisphere, only 10 gales on the average (10 per cent.) have been reported. The fact is liere develojied that the atmosphere is in a more unstable condition in the North than in the South Atlantic; that we have more calms, more rains, more fogs, more gales, and more thunder in the northern than in the southern liemisj.here. particularly between the equatur and the 55th parallel. Beyond that the influence of Cape Horn becomes manifest. ;

—

CONTENTS.

Pase

Cbspter I.

II.

III.

The

Gclf Stp.eam

••«

Influence of the Gulf Stream upon Climates

...

...

The Atmosphere

...

...

6l'^7

123

...

...

...

...

...

IV.

Land and Sea Breezes

...

...

...

...

.••

V.

Red Fogs AND Sea Dust

...

...

...

...

...

VI.

VII. Currents OF the Sea

IX.

The Open Sea

IN

...

...

...

...

13o

...

...

...

166

...

...

...

199

...

...

...

...

203

...

...

...

...

249

...

...

264

...

the Arctic Ocean

The Salts of the Ska

...

X. The Equatorial Cloud-Ring

XI. On the Geological Agency of the Winds XII.

35

On the probable relation between Magnetism and the Circulation of the Atmosphere

VIII.

^

...

...

The Depths

OF THE Ocean

XIII. The Basin of the Atlaktio

XIV. The Winds

XV. Climates

...

...

...

...

...

292

...

...

...

...

306

...

...

326 362 331

...

of the Ocean

XVI. The Drift of the Sea

...

...

...

...

...

...

...

...

...

...

XVII. Storms

405

XVIII. Routes

4]3

XIX. Brussels Conference,

XX. Force

of the Trade

etc.

...

...

•••

—

*3*^

Winds of the Southern Hemisphere—

Peculiai.ities in its Atmospheric Circulation

XXI. The Submarine Telegraph OF THE Atlantic

...

...

435

...

4ti9

—

THE

PHYSICAL GEOGRAPHY OF THE SEA.

CHAPTEE

I.

THE GULF STREAM. Us

Colour, §

2.

— Theories, — Captain 5.

Livingston's,

—

6.

— Dr.

Franklin's, 7.

Admiral Smyth and Mediterranean Currents, 8. Trade Winds not the Cause of the Gulf Stream, 9.— Drift of Bottles, 12.— Sargasso Sea, 13.— Hypothetical System of Currents, 19. Galvanic Properties of the Gulf Stream, 26. SaltGulf Effects produced upon Currents by Evaporation, 32. ness of ditto, 29. Stream Roof-shaped, 39. Effects of Diurnal Rotation upon Running Water, 42.— Course of the Gulf Stream not altered by Nantucket Shoals, 52. The Trough in the Sea through which the Gulf Stream flows has a Vibratoij MoStreaks of Warm and Cold Water in the Gulf Stream, 57. Runs tion, 54. up Hill, 59. -A Cushion of Cold Water, 60.

— —

—

—

—

— —

—

There it

never

flows. its

i.s

and

fails,

Its

cmTent

tain,

and

In the severest di'oughts

a river in ihe ocean.

of

is

its

Stream.

flow of water.s.

its

is

is

never over-

it

bottoms are of cold water, while

The Gnlf of Mexico

warm.

mouth

There

sippi or the

in the mightiest floods

banks and

in the Ai'ctic Seas.

in the world

Its current is

Amazon, and

chapteu

its

is its

It is the

form-

stream.

Gulf

no other such majestic

more rapid than the

Missis-

volume more than a thousand

times greater. Its waters, as coasts, are

far out

from

tlie

,

marked, that their

Gulf as the Carolina

They

of an indif'O blue.

line of junction

are

,

with the

so

distinctly

common

sea

§

2

colour of its WBlcra

THE PHYSICAL GEOGRAPHY OF THE

2 cnociprsa

may be may be

water vessel

by the

traced

is

Often one half of the

eye.

perceived floating in Gulf Stream water,

while the other half

sharp

SE.\.

in

is

common water want

the line, and such the

of the sea

so

;

of affinity between

those waters, and such, too, the reluctance, so to speak,

on the part of those of the Gulf Stream to mingle with the

common water

of the sea.

At the salt-works

§ 3

and along the shores

in France,

by

of the Adriatic, where the "salines" are can-ied on

the process of solar evaporation, there or pools through which the water froui

3a;tr.e«..

the sea, and

longer

reduced to the briny

the hue of

is

its blue,

about to commence, when the

puts on a reddish

Stream are which they

passed as

it

The grows,

until crystallization

now

deep blue water

the waters of the Gulf

and hence we can account

indigo blue which

comes

than the watei"S of the sea through

Salter^

flow,

Now

tint.

it

state.

exposed to evaporation the Salter

it is

and the deeper is

is

is

a series of vats

is

all

navigators observe

ofl"

for the

deep

the Carolina

coasts. §

4

These

salt-malcers

are

the

in

of judging

habit

the richness of the sea water in salt

greener the hue, the fresher the water.

by

colour

its

We

—

have in

of

the

this.

an explanation of the contrasts which the waters ^ of the Gulf Stream present with -those of the Atlantic, as

Contrast ])erhaps, ^ i with other waters.

well as of the

Polar waters regions,

and

;

lio'ht

also

o-reen of the

North Sea and other

of the dark blue of the trade-wind

especially of the Indian Ocean,

which poets

have described as the "black waters." §

5

What

is

the

cause

puzzled philosophers.

of the

Many ^

Gulf Stream has always

are the theories

§-29.

and numer-

THE GULF

3

STREA^r.

ous the speculations that have been advanced with regard chapter to

Modern

it.

investigations

ginning to throw some light upon the subject, though is

not yet

the father of the Gulf Stream.

produce

'—

all

clear.

Early writers maintained that the Mississippi Kiver v.-as

—

and examinations are be-

it

;

for its velocit}', it

Its floods,

was

they

held, could be

puted by the rate of the cm-rent of the

said,

cause,

com-

liver.

Captain Livingston overturned this hypothesis by showing that the volume of water which the Mississippi River

empties into the Gulf of Mexico

Theories

§ 6 captain

not equal to the three-

is

thousandth part of that which escapes from

it

through

the Gulf Stream. ]\Ioreover, the

water of the Gulf Stream

of the Mississippi fresh tiiat

just as

much

;

is

salt

—

that

and those philosophers^ forgot

salt as escapes

from the Gulf of Mexico

through this stream, must enter the Gulf through some other channel from the

main ocean

for, if it

;

Gulf of Mexico, in process of time, miless

bed at the bottom, or was fed I'elow fresh

—

neither of which

is

Avith

probable

did not, the

it

had a

salt

salt springs fi'om

—would become

a

water basin.

The above quoted ai-gument

;

and upon the remains

had so completely overturned

of the hypothesis which he

he set up

Captain Livingston,

of

however, was held to be conclusive

another, which, in turn, has been upset.

In

it

he ascribed the velocity of the Gulf Stream as depending 'J

on the motion of the sun

in the ecliptic,

and the

influ-

ence he has on the waters of the Atlantic."

But the opinion that came received and deep rooted in the

»

§5.

to be

mind

the most generally of seafaring peoph^

§

7

THE PHYSICAL GEOGRAPHY OF THE

4 CBAFTER

—

was

One repeated by Dr. Franklin, and

tliB

that the Giilf Stream

'—

SEA.

is

wliicli

held

the escaping of the waters that

lin's opin-"

have been forced into the Caribbean Sea by the trade-

thetraTe-

winds, and that

^'"''*'

it

the pressure of those winds upon

is

the water which forces up into that sea a head, as

it

Avere, for this stream.

"We

know

of instances in which waters have been ac-

cumulated on one side of a lake, or

AA-inds

may

its

tradeinitial

velocity,

but are they of themselves adequate to such an

effect?

To

my

mind, the laws of Hydrostatics, as at

present expounded, appear

Kotcon-

one end of a canal,

give the Gulf Stream

to

assist

in

The pressure of the

at the expense of the other.

conclusion that

it

is,

by no means

to warrant the

unless the aid of other agents also

be brought to bear. §

Admiral Smyth, in

8

teiTanean

(p.

feet Strait of

known

above

its

memoir on the Medi-

162), mentions that a continuance in the

Sea of Tuscany of has been

his valuable

"

gusty gales" from the south-west

to raise its surface

ordinary

no

less

than twelve

This, he says, occasions a

level.

strong surface drift through the Strait of Bonifaccio.

But

tonifaccio

in this

we have nothing

and narrow channel-way

like the

any pond

;

no

deej)

to conduct these waters off like

a miniature river even in that

sea,

but a mere surface

up

of water in

or gulf above the ordinary level.

The Boni-

flow, such

its differ-

Gulf Stream

as usually follows the piling

faccio Current

does not flow like a "river in the sea"

t-cc finm t'ffniit

across the Mediterranean, but

as

it

spreads itself out as soon

passes the Straits, and, like a circle on the water,

loses itself

room.

it

by broad spreading

as soon as

it

finds sea-

THE GULF STREAM.

5

Supposing the pressure of the waters that are forced into the Caribbean Sea

by

cause of the Gulf Stream, that Sea and the Mexican Gulf

much higher

should have a

support "a gi-eat degree of elevation."

immense

its

Major Rennell

river descending from

Now, we know very nearly

a higher level into a plain."

the average breadth and velocity of the Gulf Stream in the Florida Pass.

approximation,

the

We

"

than the Atlantic.

level

Accordingly, the advocates of this theory require for

likens the stream to " an

chapteh

the trade-winds to be the sole

know, with a

also

and breadth of

velocity

waters off Cape Hatteras.

like degree of

same

tlie

Their breadth here

Breadth city in tiie

Pass,

about

is

" seventy-five miles against thui-y-two in the " Nari'ows

of the Straits,

and

their

mean

velocity

is

three knots off

Hatteras against four in the "Narrows."

This being the

off

cap-

Hatter**

case, it is

off

easy to show that the depth of the Gulf Stream

Hatteras

Bernini

is

not so great as

by nearly 50 per

instead of descending,

an inclined

cent.,

in the "

and

uj')

Narrows

" of

that, consequently,

bed represents the surface of

plane, with its descent inclined

toward the south, tlie

its

it is

from the north

which plane the lower depths of

stream must ascend.

If

we assume

its

depth

offitsdeptu offSemJni.

Bemini* to be two hundi-ed fathoms, which are thought to be within limits, the above rates of breadth

city will give one

depth off Hatteras. Straits are

and

hundred and fourteen fathoms

below the

The waters, level

therefore,

velo-

for its

which in the

of the Hatteras depth, so far

from descending, are actually forced up an inclined plane,

its

waters

ascend *

Professor Bache reports that the officers of the Coast Survey have soundei

with the deep sea lead, and ascertained ary, 1856).

its

depth here to be 370 fathoms (Jaui-

THE PHYSICAL GEOGRArHY OF THE

6 CHAPTER

——

.

whose submarine ascent

jrara cun-

trasted

with the

Gulf

not

less

than ten inches to

tlie

mile.

The Niagara

§10 TheNia-

is

SEA.

is

an "immense river descending into

But instead of preserving x o its character in Lake Ontario as a distinct and well-defined stream for several hundred miles, it spreads itself out, and its waters

g^

plain." ^

Stream.

Why

are immediately lost in those of the lake.

not the Gulf Stream do the same true

itself, it is

by broad

but, instead of mingling

;

spreading, as the

into the northern lakes do,

"

with the ocean

immense rivers" descending

its

waters, like a stream of

ocean, preserve a distinctive

in the

should

It gi-adually enlarges

?

oil

more

character for

than three thousand miles. §

Moreover, wliile the Gulf Stream

11

north from there Currents

meeting '^

is '-'

divides

warm

itself,

running to

is

level

at

t];e

the south,

down from the north midway the ocean,

a cold current coming

meeting the it

supposed

its

elevated

;

waters of the Gulf

and runs by the

side of

them right back

into those very reservoirs at the south, to which theory

gives an elevation sufficient to send out entirely across

the Atlantic a jet of warm water said to be more than three

thousand times

gi^eater in

volume than the Mississippi River.

This current from Baffin's

winds to give unfavourable to

below the

And

and and

for a great part of the

far

there

is

If so,

way

beyond the propelling

it is

reacli oi

every reason to believe that

with other polar currents,

to the Gulf Stream.

causes?

trade-

a head, but the prevailing winds are

it,

surfiice,

any wind. this,

it

Bay has not only no

is

quite equal in volume

Are they not the

effects

what have the trade winds

the one more than the other

?

to

of like

do with

THE GULF It

is

custom often

a

7

STIlEiJ^r.

practised

by seafaring people

throw a bottle overboard, with a paper, stating the

to

lime and place at which

it

is

cEiFTEB

—

In the absence of

done.

Infonna-

other information as to currents, that afforded

na\^gators

little

„

.

.

mute

tracks behind them,

is

it

botiies.

and their routes can not

seeing where they are found, some idea as to their course.

tion de-

rived f:tm

They leave no

But knowing where they were

be ascertained.

these

,

of gi-eat value.

is true,

by

Straight lines

may

may

cast,

and

be foi-med

at least be drawn,

showing the shortest distance from the beginning to the

end of their voyage, with the time elapsed. Beechey,

wa}^, the tracks of it,

it

Admiral

has prepared a chart, representing, in

E,.N.,

more than one hundi-ed

appears that the waters from every quarter of the

Atlantic tend toward the Gulf of Mexico and Bottles cast into the sea tlie

tliis eher_

From

bottles.

New

midway between

its

stream.

the Old and

Worlds, near the coasts of Europe, Africa, and

America, at the extreme north or farthest south, liave

been found either in the "West Indies, or the British Isles,

or within the

well-known range of Gulf Stream

waters.

Of two

cast out together in south latitude on the coast

of Afiica, one

was

foilnd on the island of Trinidad

other on Guernsey, in the English Channel.

;

tlie

In the ab-

sence of positive information on the subject, the circumstantial evidence that the latter

the Gulf

is

all

but conclusive.

performed the tour of

And

there

is

reason to

suppose that some of the bottles of the admiral's chart liave also

performed the tour of the Gulf Stream

;

without being cast ashore, have returned with the

Admi-ai

then, drift

along the coast of Africa into the inter-tropical region

;

THE PHYSICAL GEOGRAPHY OF THE

8 OHAPTER thence

—

SEA.

through the Caribbean Sea, and so ou with the

Gulf Stream again.

Another

bottle,

(Plate VI.)

thrown over

off

Cape Horn by an

American master, in 1837, has been recently picked up on the coast of of the

An

Ireland.

inspection of the chart, and

of the other bottles, seems to force the con-

di'ift

clusion, that this bottle too

went even from that remote

region to the so-called hlglier level of the Gulf Stream reservoir. §

Midway

13

the s»-;"»3

is

the Atlantic, in the triangular space between Canaries,

A2K)res,

the Sargasso Sea.

and the Cape de Verd (Plate

Islands,

Covering an area

VI.)

equal in extent to the Mississippi Valley,

it is

so thickly

matted over with Gulf Weeds (fucus natans), that the speed of vessels passing through

When

the companions of

it is

often

Columbus saw

much

it,

retarded.

they thought^

marked the limits of navigation, and became alarmed. To the eye, at a little distance, it seems substantial enough it

to

walk upon.

Patches of the weed are always to be

seen floating along the outer edge of

Now,

of cork or chaff, or

if bits

any

tb.e

Gulf Stream.

floating substance,

be put into a basin, and a circular motion be given to

the water,

all

the

light

substances

crowding together near the centre of the there

is

the least motion.

Just such a

Atlantic Ocean to the Gulf Stream Diuc^ vered by coiMib'js.

Sea

is

this

weedy

the centre

this day,

pool,

basin

and

i\\Q

Columbus

sea in his voyage of discovery

remained to its

of the wliud.

;

;

to

be found

will

where is

the

Sargasso

first

tb.ere

found it

has

moving up and down, and changing

position like the cahns of Cancer, according to the

seasons, the storms,

and the winds.

Exact observationa

THE GULF as to its limits years,

assui'e

and

mean

its

therefore, this

level in

one

be

why

so,

paii: of its

Nay, more

;

is

1-

anV^'si'""*'

bottle

inforaiation.

If,

give the endless current a higher

course than another

at the very season of

the Gulf Stream

for fifty chaptkk

by the

con-oborated

is

and other sources of

Plate VI.,

back

has not been

position

This indication of a circular

motion by the Gulf Stream

by

9

their range, extending

us that

altered since that time.

chart,

STREAir.

?

the year

when

§

14

rushing in greatest volume through

the Straits of Florida, and hastening to the north with

the greatest rapidity, there

is

a cold stream from Baffin's

coia stremii St

Bay, Labrador, and the coasts of the north, running to

Where

the south with equal velocity.

is

the trade-wind

n om

nly

that gives the higher level to Baffin's Bay, or that even ]n-esses

upon, or assists to put this current in motion

The agency of winds in producing currents sea tb.e

of

must be very

These two cuirents meet off

partial.

Grand Banks, where the

bergs,

One part

latter is divided.

underruns the Gulf Stream, as

it

is

shoA^Ti

by the

ice- itsdire>

which are carried in a direction tending across

The probability

course.

?

in the deep

is,

that this

" fork"

its

on

flows

toward the south, and runs into the Caribbean Sea, for the temperatui'e of the water at a

been found far below the crust,

little

depth there Las

mean temperature

and quite as cold as

of the earth's

at a corresponding depth off

the Arctic shores of Spitzbergen.

More water can not run from the equator or pole than to

it.

the Gulf Stream,

If

we make

we ought

produce the Polar flow part,

and

;

tlie

the trade-winds to cause

to have

some other wind

15

currenu

to encedby

but these currents, for the most

for great distances, are

§

submarine, and there-

THE PHYSICAL GEOGRAPHY OF THE

10

CHAPTKR fore bej'ond

the influence of winds.

appear that winds have

little

to

SEA.

Hence

should

it

do with the general

system of aqneous circulation in the ocean.

The other

16

fork"

runs between us and the Gulf

Stream to the south, as already described.

As

has been traced,

it,

vp §

"

it

warrants the belief that

to seek the so-called Jiigher level of the

power

The

necessary

to

overcome

far as

it

too,

runs

Mexican

Gulf.

the

resistance

opposed to such a body of water as that of the Gulf

running

Stream,

thousand

sevei-al

miles without

any

renewal of impvilse from the forces of gi'avitation or any

known cause, is truly surprising. It we have an argument for determinincr,

happens

other

so

that

"n*ith

consi-

Resistance U) the Gull

dcrablc acciu'acy, the resistance which the waters of

^tieara.

stream meet with in their motion toward the to the diurnal rotation, they are carried

earth on

its

around with

tlie

axis toicard the cast with an hoiu'ly velocity

of 07ie hundred

and

fifty-seven* miles gi-eater

enter the Atlantic than

of Xewfoimdland

;

for,

when they

an'ive

ofi'

in consequence of the

of latitude between the parallels of tliese rate of

tliis

Owing

east.

two

motion around the axis of the earth

from nine hundred and

fifteen-]-

to seven

when they the

Banks

difference

places, their is

reduced

hundred and

fifty-eight miles the hour. §

17

Therefore this

we suppose Banks

in

it

immense

to pass

volixrne

of water would,

if

from the Bahamas to the Grand

an hour, meet with an opposing force in the

* In this calculation tLe earth

is

treated as a perfect sphere, with a diameter

of 7925-56 miles.

t Or 915'26 to 758 '60. (»d the latter parallel, the current has an east pet ff about one and a half miles the hour, making the true velocity to the east and on the axis of the earth, about seven hundred and sixty miles an hour at the ;

(irand Baiika.

THE GULF STREAM.

of resistance sufficient, in the aggregate, to retard chapteb

Bliape it

11

two miles and a half the minute in

its

eastvvardly rate.

If the actual resistance be calculated according to received laws,

it

pressure

gentle trade- winds be to such resistance, and to

assigned

we

And

found equal to several atmospheres.

will be

by analogy, how inadequate must the them

tlie effect

therefore, in the proposed inquiry,

If,

?

of the

search for a propelling

higher level of the Gulf,

power nowhere but

we must

the

in

admit, in the head of

water there, the existence of a force capable of putting in motion, and of driving over a plain at the rate of four miles the hour,

all

the waters, as fast as they can be

brought down by three thousand^ such streams as the Mississippi River,

come

tlie

—

a power at least sufficient to over-

resistance required to reduce from

and a half

to a

few

feet per

two miles

minute the velocity of a

stream that keeps in perpetual motion one fomih of

all

the waters in the Atlantic Ocean.

The iect, •>

from observation on

facts,

afford us at best but a

'

no means

sufficient

to

this

interesting sub-

mere glimmer of o

make any mind ^

light, o '

clear as to

of the Gulf, or as to the sufficiency of

hiqJier level ^

_

by J a

any

.

other of the causes generally assigned for this wonderfid stream.

If

it

be necessary to resort to a higher level in

the Gulf to account for the velocity off Hattei'as, I cannot perceive wliy tro

we

should not, with like reasoning, resort

a higher level off Hatteras also to account for the velo-

city off the

throughout reductio

Grand Banks, and thus make the Gulf Stream, its

circuit,

a descending

cui-rent, and,

ad absurdum, show that the

not adequate to the effect ascribed.

by the

trade- winds are

Moreover, the top

§

18

^°^^^tainty as *° "'®

cause of ^^^ ^uif stream.

THE PHYSICAL GEOGRAPHY OF THE SEA

1 2

Gulf Stream runs on a level with the ocean, there-

CHAPTER of the

know

fore ive §

19

When

Let

tration.

having

size,

wanting,

us, therefore,

a

it

often happens that hypo-

the purposes of

in their stead,

serve,

thesis \vill Hj-pothe-

not a descending current.

it is

facts are

solid

illas-

suppose a globe of the earth's

nucleus,

and covered

all

over

with water two hundred fathoms deep, and that every of heat

source that

its fluid

and cause of radiation be removed,

On

throughout.

so

temperatiu-e becomes constant and uniform

such a globe, the equilibrium remain-

ing undisturbed, there would be neither vnnd nor current. §

20

now

Let us tropics, to

becomes

suppose that

disturbed,

rents and counter cm-rents

—

the

oil,

the

and a general system of

poles,

cur-

would be immediately com-

an unbroken sheet on the

in

rimning toward the cuiTent,

the water within

The aqueous equilibrium of the planet

oil.

would thereby be menced

all

the depth of one hundred fathoms, suddenly

surface,

and the water, in an under

The

toward the equator.

oil

supposed, as

is

it

reaches the polar basin, to be reconverted into water^ and tlie

water to become

coi-n,

rising to the

oil

as

it

crosses

Cancer and Capri-

smface in the intertropical regions, and

returning as before. §

21

Thus, without tuind,

we should have

a perpetual and

uniform system of tropical and polar currents. sequence of diurnal rotation of the planet on each particle of

oil,

In conits

axLs,

were resistance small, would approach

the poles on a spiral turning to the east, with a relative velocity gi-eater tlie pole,

and

gi-eater, until

and whirl about

it

finally

it

would reach

at the rate of nearly a tliou-

^

THE GULF

1

Becoming water and

Band miles the hour. velocity, it

STREAil.

would approach the

tropics

by a

inverted spiral, turning toward the west. principle here alluded to, all ciurents

3

losing its chapter

—

similar but

Owing

to the

from the equator to

the poles should have an eastward tendency, and

all

from

the poles toward the equator a westward.

Let us now suppose the thetical globe to

bottom of our size,

nucleus of this hj'po-

solid

and

seas,

and

in all respects, as to figure

to represent the shoals

and islands of the

the coast lines and continents of the

as

22

§

assume the exact form and shape of the

sea, as

earth.

uniform sj'stem of cuiTents just described would

well

The

now

be

Results of

hypothesis

interrupted

by

obstnictions

and

local causes

of various

kinds, such as unequal depth of water, contour of shorelines, &;c.

;

gi'eater in

there to

and we should have at certain places currents

volume and velocity than

and from either pole and the equator.

the cold waters of the north, and the Gulf,

we

But

at others.

still

would be a system of currents and counter currents

made

specifically lighter

by

warm

Now, do not waters of the

tropical heat,

and which

see actually preserving such a system of counter cur-

rents, hold, at least in

supposed water and

oil

some

degi'ee,

the relation of the

?

In obedience to the laws here hinted

at,

there

is

a

constant tendency^ of polar waters toward the tropics, and of tropical waters

toward the

poles.

Captain Wilkes, of

§

23

Tendency and cal

tlie

tropi-

watera

United States Exploring Expedition, crossed one of

these hjqjerborean under-cm-rents

two hundred miles

in

breadth at the equator.

Assuming the maximum velocity at five knots,

and

its

of the Gulf

Stream

depth and breadth in the Narrows ' 1

Plate IX,

§

24

A'^nmea Telocity

THE PHYSICAL GEOGRAPHY OF THE

14 CHAPTER of

Bemini

SEA.

would

before/ the vertical section across

as

present an area of two hundred millions of square feet

moving of'recm^ g:iavity.

The Qf

at the rate of seven feet three inches per second.

difference of

specific

gravity between the volmne

Gulf Water that crosses this sectional line in one

and an equal volume of water

second,

at

ocean

the

temperatiu'e of the latitude, supposing the two volumes to

be equally

salt,

millions

fifteen

is

of pounds.

If

these estimated dimensions (assumed merely for the pur-

mthin

poses of illusti'ation) be

limits,

then the force per

second operating here to propel the waters of the Gulf

toward the pole

tlie

is

equilibrating tendency

due

to

millions of pounds of water in the latitude of

fifteen

This

Bemini.

in one scale of the balance.

is

other, the polar scale, there gi'avity

is

In the

the diflference of specific

due an equal volume of water in the polar basin,

on account of

its

degree of temperature as well as of

salt-

ness. §

25

Author's

In investigating the currents of the

such agencies

seas,

As a

should be taken into account.

cause,

I

doubt

opinion.

whether

one

this

sufficient

is

of

itself

to

produce

a

stream of such velocity and compactness as that of the Gulf;

for,

assuming

the proposition

is

sufficient to

estimated discharge to be correct,

almost susceptible of mathematical de-

inonsti'ation, that to

consequence of

its

its

di"ive,

overcome the resistance opposed in

velocity

would require a

at the rate

force at least

of three miles the hour,

ninety thousand millions of tons

up an inclined plane

having an ascent of three inches to the mile.*

Yet

the very principle from which one of these agents * Supposing there be no resistance from frictiju.

heat, is

de-

;

THE GULF

STREiUr.

1

5

admitted to be one of the chief causes of those chapteh

rived, is

winds which are said

The chemical

to be the sole cause of this cuiTent.

properties, or, if the expression be admis-

of the Gulf Stream waters, the oqalvanic properties IT L come fi-om their fountains, are different, or rather

sible, ^

as they •^

more so,

intense,

they

than they are in sea water generally.

may have

viscosity that

26

chemical properties "^ '« waters.

If

a peculiar molecular aiTangement or

i-esists

tiie

differing in temperature fact,

§

admixtui'e of other sea waters

and

It is a well

saltness.

known

when put in mix of themselves, but Nor do large volumes

that waters of different temperatures,

the same vessel, do not readily require the process of agitation.

of water in motion readily admit of the admixture of

water at

In

18

rest. 4;

3 the Secretary of the

Navy

took measm-es fjr

Experi-

ments on

procuring a series of observations and experiments with

sea water.

regard to the corrosive effects of sea water upon the copper sheathing of ships.

With

these researches were carried

and

it is

patience, care,

on

and labour,

for a period of ten years

said the fact has been established, that the cop-

per on the bottom of ships cruising in the Caribbean Sea

and Gulf of Mexico water upon

it,

suffers

more from the action of sea

than does the

co]->per

anv other part of the ocean. ^

of sliips cruising in

In other words, the

salts

Oai'^an'c

propertied

of these waters create the most powerful galvanic battery that

—

is

found in the ocean.

Now,

it

may

be supposed

—

other things being equal

that the strength of this galvanic battery in the sea

depends in some measure upon the proportion of that the sea waters hold in solution, [lerature.

and

also

salts

upon tem-

§

27

THE PHYSICAL GEOGRAPHY OF THE

16

cHArrKR

If,

tliis

absence of better

in the

therefore,

SEA.

information,

suggestion be taken as a probability as to the origin

of these galvanic properties,

we may go

a step farther,

and draw the inference that the waters of the Gulf Stream, as they rush out in such volume and with such Chemical

vclocitv into the Atlantic, have not only chemical affini-

themselves, but, having more

ties peculiar to

higher

salts,

temperature, and a high velocity, they are not so per-

meable to water differing from them in

these respects,

all

and, consequently, the line of meeting between

them and

the other water of the ocean becomes marked.

This

the case with almost

Wliere

all

waters in rapid motion.

is

the Mississippi and Missouii rivers come together, there is

a similar reluctance on the part of their waters to mingle,

for the line of

meeting between them can be traced for

miles below the junction of the two rivers. §

29

The story

told

by the

indicates a higher point

sea water generally, Dr.Tho-

copper^

and the salometer confirms

colour''

it.

Dr.

Thomassy, a French savant, who has been extensively engaged in the manufactm-e of

txperir.

and the blue

of satm-ation with salts than

me

informs

tion,

salt

by

evapora-

solar

that on his passage to

the

United

States he tried the saltness of the water with a most delicate instrument

:

he found

contain 8^ per cent, of salt 4iV per cent.

per

the

with

West

and

in the

all

in the

Bay

;

Gulf Stream,

off Charleston,

Amazon and

the intermediate rivers, and

Indies,

had lent

of Biscay to

in the trade-wind region,

notwithstanding the

cent.,

sippi,

;

it

4

the Missis-

tlie

clouds of

their fresh water to dilute the

saltness of this basin. §

SO

Now, the question may be

asked, AYhat should

make

THE GULF the, waters of the

Mexican

STEEA:\I.

1

and Caribbean Sea

Giilf

7

Salter chapteb

_

than the waters of like temperature in those parts of the ocean through which the Gulf Stream flows

There are physical agents that are in is

to

and

make heavier,

employed by and

;

to be at

work

the waters in one part of the ocean Salter

and

another part lighter and

in

than the average of sea water.

structures

?

of the ocean, the tendency of which

parts

different

known

less

§

31

physica!

^^^""''^

salt

These agents are those matter for their

sea-shells in secreting solid

they are also heat* and radiation, evaporation

precipitation.

In the trade- wind regions at

sea,'

evaporation

is

gener-

ally in excess of precipitation, while in the extra-tropical

regions the reverse

down more water

is

the case

that

;

which

in

32

Evapora-

the clouds let

is,

there than the winds take

and these are the regions

§

up again

;

Stream

the Gulf

enters the Atlantic.

Along the shores of carefully made,

the

where experiments have been

India,

evaporation from

to three-fomi^hs of an inch daily.

Suppose

wind region of the Atlantic

amount

inch, that feet.

to

it

Now^ a

to only half

woidd give an annual evaporation of

is

taken up, the

33

§

34

in the trade-

In the process of evaporation from the

water only

§

the sea amounts

an

fifteen

sea, fresh

salts are left behind.

and as

layer of sea water fifteen feet deep,

broad as the trade-wind belts of the Atlantic, and reaching across the ocean, contains an immense amount of

The great equatorial current

(Plate VI.)

salts.

which sweeps

from the shores of Africa across the Atlantic into the Caribbean Sea

is

a sm-face current; and

* According to Dr. Marcet, sea water contracts 1

Plate VIII,

2

may down

it

not bear

to 28°.

THE PHYSICAL GEOGRAPHY OF THE

18

SEA.

CHAPTER into that sea a large portion of those waters that

the

satisfied Reason

for

jf gQ

saltness of

caiibbean Sea.

—

^j^j

trade-winds with

thirsty [^

probablv does ^ i

—have we

have

vapour?

saltless

not detected here

of an accent that does tend to make the the foot-prints ^ n waters of tlie Caribbean Sea Salter, and therefore heavier .

than the average of sea water at a given temperatui'e It ciple

upon which

this

reasoning depends

whether the annual evaporation

from

concerned,

is

the trade-wind

regions of the Atlantic be fifteeH, ten, or five

layer of water, whatever be

its

by the clouds they take

it

in the

and pour

not

all

same place whence

it

it

down

tropical regions of the earth

is

—and

is

in showers

—on

on the land more water

soil to

came.

is let

The

feed the springs,

rest

down than sinks down

and retm'n through

Suppose the excess of precipi-

tioa.

tation in these extra-tropical regions of the sea to

but twelve inches, or even to but two

added

two

But

upon the extra-

the rivers to the sea.

inches or

evapo-

is

poured back

Effects of

to

The

the land as well as in

taken up into the clouds again.

through the

feet.

thickness, that

rated from this part of the ocean,

the sea

?

immaterial, so far as the correctness of the prin-

is

inches, as the case

to the sea in those parts,

may

—

it

amount twelve

is

be, of fresh

water

and which therefore tends

to lessen the specific gi-avity of sea water there to that

extent,

and

to produce a double efiect,

reason that what

is

taken from one

for the

scale,

simple

by being put

into the other, doubles the difference. J

Now

35

that

we may form some idea as to left by the vapour that

ence which the salts

the influthe trade-

winds, north-east and south-east, take up from sea water, is

calculated to exert in creating currents, let us

make

a

—

THE GULF STREAM. partial calculation to sliow liow

solution before

in it

was yet

much

was taken

it

it

is,^

we

vapour held

salt this

—

embrace an area of at

and the yearly evapora-

The

will suppose, fifteen feet.

salt

contained in a mass of sea water coveiing to

is

chapter

The north-east

in the state of sea water.

least three million square miles;

that

9

up, and, of coiu'se, while

trade- wind regions of the Atlantic

tion from

1

supposed tion in tu^

regions."

the depth of fifteen feet an area of three million square miles in superficial extent, would be sufficient to cover

the British islands to the depth of fourteen

feet.

water supplies the trade-winds with vapom",

becomes

infer

and as

Salter,

aggregation

among

from the

fact,^

are reluctant to

it

becomes

its particles

it

mix with those of the

stated,

ocean.

;

or whether

whether

trade- wind § 36 it

be from

and in consequence of which the

waters of the Gulf Stream are

chamiel

we may

that the waters of the Gulf Stream

waters to remain on the surface, fact just

this

Salter the forces of

are increased, as

Whatever be the cause that enables these the

As

therefore

it

be from the fact that the expan-

zone

compensate for this increased saltness

;

sufficient

is

or whether

it

to

be

from the low temperature and high saturation of the submarine waters of the inter-tropical ocean be owing to

all

do

know

surf\ice,

that they go into the

surface cun-ent.

;

or whether

of these influences too'ether that these

waters are kept on the

On

suffice

it

to

we

Sea^ as

a

and through

it,

Caribbean

then- passage

to say,

they intermingle with the fresh waters that are emptied into

the sea from the Amazon, the Oronoco, and the

Mississippi,

and from the >

§33.

clouds,

"

§27.

tersfoma

held together in their cmTent

sion from the heat of the torrid

it

Tradewind wa-

and the 8

§34.

rivers of the

THE PHYSICAL GEOGRAPHY OF THE

20

is Mixture of wa-

fresh

An immense volume

round about.

CHAPTER coasts

supplied from these sources. •

i

i

SEA.

of fresh water

make

It tends to i

i

sca Water, that the trade-winds have been

the

•

i

playmg upon

ter.

and

warmer, and lighter

di'iving along, less briny,

the waters of these large inter-tropical streams are

This admixture of fresh water

than sea water.

;

for

warmer leaves

still

the Gulf Stream a brine stronger than that of the extratropical sea generally,

but not quite so strong as that

of

the trade- wind regions.^ It is

Effect of

the tradewinds,

assume that the trade- winds, by their

safe to

constant force, do assist to skim the Atlantic of the water

them with vapour, driving

that has supplied

Caribbean Sea,

whence, for causes unknown,

by the channel

of the Gulf

into the

it

escapes

it

Stream in preference

to

any

other.* §

In the present state of our knowledge

37

wonderful phenomenon

this

—

for the

of the most marvellous things in the ocean little

more than

operation which saitness of Baltic

coucemed

and

North

—we

is

one

can do

But we have two causes

conjecture.

we may

concerning

Gulf Stream

safely

in

assume are among those

One

in producing the Gulf Stream.

of these

.

.

in the increased saitness of its water alter the trade-

is

winds have been supplied with vapour from or

and the other

little;

salt

which

the' Baltic

The waters of the

it,

in the diminished

is

be it much quantum of

and the Northern Seas

Baltic are nearly fi-esh

to contain only about half as

much

;

contain.

they are said

salt as sea

water does

generally. 5

Now

38 *

The

here

we

have, on one side, the Caribbean Sea

fact is familiar to all concerned in the inanufacture of salt

poratiou, u at the first

show

of crystallization »

§29.

commeuees

by

solar eva-

at the surface.

THE GULF

21

STREAJNI.

and Gulf of Mexico, with their waters of brine other, the

gi-eat

two

Sea, the

latter

than brackish. f is

with waters

In one

heavy; in the other

ocean intervenes

maintain

on the

and

;

tliat

are but

is

—

1-

water

Between them the

light. is

chaptkr

more

little

set of these sea-basins the it

but water

;

level

its

;

Polar basin, the Baltic and the North

bound

to seek

and to

we unmask one

here, therefore,

one agent conceiT)ed

agents concerned

of the

What is it, it

causing the

— —we

the influence of this agent

is

and

is

in

to

what extent does

it

go

Gulf Stream,

that

is,

can not say

at least one of the agents concerned.

speculate as collecting

we may

great ;

stream.

only

Moreover,

as to all the agencies concerned in

have supplied the trade-

waters, that

these

how

in causing

winds with vapour, into the Caribbean Sea, and then in driving

them

across

sure, that the salt

the Atlantic

—

of this

we may be

which the trade-mnd vapour leaves

behind in the tropics has to be conveyed away from the trade-wind region, to be mixed up again in due proportion with the other

the Ai'ctic

water of the sea

Ocean included

the ofiices which, in the

assigned to

As

—

the Baltic Sea and

that these are some of

rmming ofl" through the To convey them away is doubtless one of

the waters at least which

Gulf Stream.

—and

we

see

economy of the

ocean, has been

it.

to the temperature of the Gulf Stream, there

is,

in Temper*-

a winter's day, off Hatteras, and even as high up as the

Grand Banks of Newfoundland

in

mid

ocean, a difference

t The Polar basin has a known water area of 3,000,000 squai-e miles, aud an unexplored area, including land and water, of 1,500,000 square miles. Whetlier the water in this basin be more or less salt than that of the inter-tropical seas, we know it is quite dififerent in temperature, and difference of temperature will beget currents quite as readily as difference in saltuess, for change in specifio gravity follows either.

;

THE PHYSICAL GEOGRAPHY OF THE

22 CHAPTER

between

its

and even

'

SEA.

waters and those of the ocean near by of 20°,

we know, expands by heat, and may more than com-

Water,

80°.

here the difference of temperature

pensate for the difference in saltness, and leave, therefore, the waters of the Gulf Stream lighter by reason of their

warmth. §

If

39

they be

they should therefore occupy a

lighter,

higher level than those through which they flow.

suming the depth Expansion

off

As-

Hatteras to be one hundred and

fourteen fathoms, and allowing the usual rates of expansion for sea water, figures

show that the middle

or axis of

the Gulf Stream there should be nearly two feet higher

Hence the

than the contiguous waters of the Atlantic.

surface of the stream should present a double inclined

Form.

plane, from

which the water would be running do\vn on

either side as from the roof of a house.

at the top, the

As

this runs off

same weight of colder water runs

in at the

bottom, and so raises up the cold water bed of the Gulf Stream, and causes as

it

goes north.

it

to

become shallower and shallower

That the Gulf Stream

shaped, causing the waters on either side from the middle,

its

is

therefore roof-

sm-face to flow off to

we have

not only circum-

stantial evidence to show, but observations to prove. §

40

Surface

Navigators, while drifting along with the Gulf Stream,

have lowcred a boat to try the surface current.

current.

,

such

cases,

the

to the west, as it

,

boat would

.

^

di-ift

happened to be on one

side or the other

of the axis of the stream, while the vessel herself drift

In

.

either to the east or

along with the stream in the direction of

its

would course

thus showing the existence of a shallow roof-current from the middle toward either edge, which would carry the

—

THE GULF

23

STREA^I.

boat along, but which, being superfcial, does not extend chaptee

deep enough to affect the drift of the

That such

the case^

is

by the circum-

also indicated

is

—

vessel. §

41

stance that the sea-weed and drift-wood which are found in

such

along the outer edge" of the

quantities

large

Gulf Stream, are

even

never,

easterly winds, found along

simple reason

to

that to

over from

pass

up an ^

di'ift

cross the

that

side

the prevalence of

-with

inner edge

its

to

for the

Gulf Stream, and to

it

would have

they

this,

inclined ])lane, as

—and

were

'J

that

;

is,

they

,

would have

stem

to

this roof-current until

We

the middle of the stream.

they reached

Erection of drift-

wood,

&c

rarely hear of planks, or

wrecks, or of any floating substance winch

is

cast into

the sea on the other side of the Gulf Stream being found

along the coast of the United States.

and seeds from the West India

Drift-wood, trees,

islands,

are said to have

been cast up on the shores of Euro})e, but never, that I ever heard, on the Atlantic shores of this country.

We

now

are treating

The question

to

which

Gulf Stream slough

upon

floating

One cmTent

same

I ask attention

off

weed, drift-wood, and

of the effects of physical causes.

and

all

but there

effect

;

its

Why

does the

outer edge, sea-

causes of the direction of

other solid bodies that are found

it?

cause has been ;

upon

cast

is.

is

shown

anotlier

and because

it is

not, in a treatise of this kind,

never so

slight.

upon the

drift

I

allude

to be

in its roof-shaped

which tends

to

a physical agent,

it

should

be overlooked, be

its

action

now

§

42

produce the

to the effects produced

matter of the stream by the diurnal rota-

tion of the earth.

Take, for illustration, a railroad that runs nortli and 1

§ 39.

«

§ 13.

§ .^3

— THE PHYSICAL GEOGRAPHY OF THE

24;

CHAPTER south.

It

are going north on

run

south, their tendency

the track luastra-

i. e.,

is

the cars

a road, their tendency

sncli

on the east side

off

when

well kno^^^l to engineers that

is

SEA.

but when the train

;

to

ran

off

is

is

to

going

on the west side of

always on the right-hand side in our

Whether the road be one mile or one hun-

hemisphere.

dred miles in length, the effect of diurnal rotation same, and the tendency to run

off,

parallel at a stated rate of speed,

the road be long or

sliort,

you

as is

the

is

cross a given

the same

;

whether

the tendency to fly off the

track being in proportion to the speed of the trains, and

not at §

44

Diurnal

proportion to the length of the road.

all in

Now,

and velocity being taken into the

vis inertice

accouut, the tcudeucy to obey the force of this diurnal

rotation.

rotation, gi*eat in

and

to trend to the right, is proportionably as

the case of a patch of sea- weed as

the Gulf Stream, as

it is

it drifts

along

in the case of the train of cars

as they speed to the north along the iron track of the

Hudson Kiver

railway, or

The

north and south.

them from flying

any other railway that

rails restrain

but there are no

off*;-

lies

the cars and prevent rails to restrain

the sea-weed, and nothing to prevent the drift-matter of

the Gulf Stream from going off in obedience force.

The

moving

freely in

to this

slightest impulse tending to turn aside bodies

water

is

immediately

and implicitly

felt

obeyed. §

45

It

is

in

consequence

down

drift-wood coming

of this

is

so very apt

to be cast

upon the west or right bank.

reverse of

what obtains upon the Gulf Stream,

flows to the north

;

it

therefore slouo-]is

§43,

that

diurnal rotation

the ]\Iississippi

off''

This

is

the

for it

to the east.

—

THE GULF The

of diurnal

effect

STREA:M.

upon the winds and

rotation

upon the cuiTents of the sea

is

admitted by

trade- winds derive their easting from

extend to

fore,

all

25

it

—

all

—

chapter

—

the

Its effects

must, there-

it

the matter which these currents bear

on the Currents!

with them, to the largest iceberg as well as to the merest of

spii-e

that floats upon the waters, or the minut-

gi-ass

est organism that the most

detect

among

eflect

of

powerful

microscope

the impalpable particles of sea-dust.

diurnal rotation

upon

drift will

can This

be frequently

alluded to in the pages of this work.

In

its

course to the north, the Gulf Stream gradually

trends

more and more

off the

Banks of Newfoundland, where

nearly due

from

its

its coui'se

will prove,

frigid cun-ent already

It

spoken of,^with

is

its

becomes

to take this

they are

here that the icebergs

fi'om

met and melted by the warm waters Of com'se the loads of earth, stones, and gravel brought down upon them are here deposited. Captain Scoresby, far away in the north, counted five hunthe of

north,

tlie

are

Gulf

di'ed icebergs setting

out from the same vicinity upon this

Many

cold current for the south. earth, cess

shoals,

This pro-

from the north for these

and of snowing down upon them the infusoria

and the corpses of so

of them, loaded with

have been seen aground on the Banks.

of transferring deposits

" living

abundantly in the

and sloughed between

it

off in

warm

myriads

creatures" that are spawned

waters of the Gulf Stream, for burial

where the

and the great Polar current' takes '

§ 11.

"

§

U.

45

Banks

of

Newfoundf

it

think, that

I

§

arrives

.

proper course, and cause

certainly not the cause.

effect,

it

has been thought,

it

.

it

Examination

turn.

an

These banks,

east.

.

deflect

to the eastward, until

conflict

place,

land.

THE PHYSICAL GEOGRAPHY OF THE

26 CHAPTER

—

everlastingly going

is

These agencies, with time,

on.

seem altogether adequate

SEA.

the formation of extensive

to

bars or banks.

The deep

Their

made by

sea soundings that have been

ves-

fjnrjition.

of the navy tend to confirm this \de"w as to the

sels

The

formation of these Banks,

bottom of the Atlantic

Nowhere

Banks.

the south

of

these

in the open sea has the water been

found to deepen so suddenly as

bottom of the sea

north, the

greatest contrast in the

just to

is

Banks,

after passing these

precipitous descent for

its

Coming from the

here.

is

sheh^ng

but suddenly,

;

depth increases by almost a

many thousand

thus indicat-

feet,

ing that the debris which forms the Grand Banks conies

from the north. §

From

47

the Straits of Bemini the course of the Gulf

Stream (Plate VI.) describes

(as far as it

can be traced

over toward the British Islands which are in the midst of

its

waters) the arc of a gi^eat circle as neaidy as

may

Such a

very

as the Gulf

Course of the Gulf

be.

stream,

nearly the course that a cannon

from these If

it

coui'se

straits to those islands,

Stream takes could

ball,

would

it

is

be shot

describe.

were possible to see Ireland from Bemini, and to

get a cannon that would reach that

far,

the person stand-

ing on Bemini and taking aim, intending to shoot at Ireland as a target, would, direct,

48

Piumai

But there volve ou

its

axis

;

and

rotation since

,

cquator than Ireland diurnal

is,

the

rotation^ faster than

'

for difference

rest,

sight

of motion

target.

diurnal

is

rotation affects its

the earth were at

and make no allowance

between marksman and §

if

Plat€ XI.

;

earth

the

Bemini

nearer to the

is ^

does re-

,

.

gun would be moving the target, »

§ 16.

and

m .

therefoi-e

;

THE GULF

27

STREA:\r.

marksman, taking aim point blank at

the

would

He would

miss.

had shot south other words, ball

—

that

is,

to the rigld^ of his

and the

—

In

by the

this difference in the rate

trajectile force

would cause the

to the east,

mark.

actually described

would be the resultant of

of rotation

target, cHAriEB

on examination, that he

find,

the path

that

his

the former, impelling

;

ball to describe a great circle,

but one with too much obliquity to pass through the tar-

Like a ray of light from the

get.

the ball would

stars,

be affected by abeiTation. It

the case of the passenger in the

is

railroad

car

§

49

throwing an apple, as the train sweeps by, to a boy standing by the wayside.

throw straight at the boy, he

If he

illustration.

will miss, cars, will

for the apple,

partaking of the motion of the

go ahead of the boy, and for the very reason

that the shot will pass in advance of the target, for both

the

marksman and

the passenger are going faster than

the object at which they aim.

Hence we may assume tendency of

all

it

currents in

as a law, that the natural

the

sea,

the

like

natm-al

§

50

Natural teiid€iicv

tendency of

all projectiles

through the

air,

is

to describe

their cm-ves of flight in the planes of great circles.

natural tendency of

when put

in motion,

The is

to

go from point to point by the shortest distance, and

it

all

matter,

requires force to overcome this tendency.

and

electricity,

running water, and

all

ponderable or imponderable, seek,

obey

this law.

course,

and so

Electricity

may

may

Light, heat,

substances, whether

when

in motion, to

be turned aside from

its

the cannon ball or running water

but remove every obstruction, and leave the current or the shot free to continue on in the direction of the '

§i3.

first

ofcunecta curves.

THE PHYSICAL GEOGRAPHY OF THE

28

of the Gulf Stream are

must have room, and gains

warmer waters

right.

/--,

for § 56

change of

for this

In winter, the volume of cold water on

the American, or creased.

The banks

obvious.

water.

cold

The reason

in turn,

motion

is

press

made by the United

Survey indicate that there are in the threads of warmer, separated

by

them back,

preserved.

States Coast

Gulf

Stream

§2.

57

warm and

streaks of cooler water, cow water

See Plate YL, in which these are shown; they are marked '

§

streaks of

THE PHYSICAL GEOGRAPHY OF THE

82 CHAPTER x, y,

——

A may

Figure

z.

SEA.

be taken to represent a thermo-

metrical cross section of the stream opposite the Capes of Virginia, for instance; the top of the curve representing

the thermometer in the threads of the

warmer water, and

the depressions the height of the same instrument in the streaks of cooler water between; thus exhibiting, as one sails

from America across the Gulf Stream, a remarkable

series of thermometrical elevations

surface temperature of this §

These streaks,

58 as

it

from

issues

x, y, z,

and

to be an incident of the process Suppoaed

Stream gradually grow

of the

it

it

to the

have thought them by which the waters

I

cool.

calm over this stream, and that top of

in the

in the sea.

are not found in the Gulf Stream

fountain,

its

and depressions

mighty river

all

Suppose a perfect the water on the

depth of ten feet were suddenly, as

runs along in a winter's day, to be stricken by the

wand

of

some magician, and reduced from the tempera-

ture of 75° to that of 32°, the water below the depth of

ten feet remaining at 7-5° as before. cold

and heavy water sink

floor or field of ice

loaded to sinking? rise field,

to the rising

middle

?

up

this

Like a great water-tight

?

over the edges,

I think not

warm water would

would

as broad as the Gulf Stream, and And how would the warm water

By running

top?

How

;

rise

that the cold would go

out under this floor or

and flowing back to the

on the contrary,

I

up here and there in

down

suppose the streaks,

in streaks or seams.

and

The

would be not unlike what we see going on in a fountain which is fed by one or more bubbling springs We can see the warm water rising up in a from below. process

column from the

orifice

below, and in winter the water

— GULF

TTIE

on the top

grows cool and then

first

S3

STREA]VI.

Now, ima-

sinks.

cHAriER

L

giue the fountain to be a long and narrow stream, and this orifice to be a fissure runnincr along at the

the middle of

it,

can well imagine

up

rising

the

all

and feeding

it

warm

with

bottom in

We

water.

there would be a seam of water

tliat

way

middle of the stream, and

in the

that a delicate thermometer would, in cold weather, show

a marked difference of temperature between the water as

up

it rises

in this seam,

and that going down on either

Now,

side after it has been cooled.

if

ginary stream broader, and place at a other fissure parallel with the

warm

we make our imalittle

and

first,

distance an-

also supplying

water, there would be between the two a streak of

cooler water descending after having parted

with a cer-

and thus we would

tain degree of heat at the surface,

have repeated the ribbons of cold and

warm water which

the Coast Survey has found in the Gulf Stream.

The hottest water lightest

;

as

it rises

poration and exposure,

by

Gulf Stream

in the

to the top,

it

when

the surface

fresh supplies of hot water

Winter

is

cooled both

is

also

the

by

eva-

Stream

day, off

the waters at

from below. the

surface

Cape Hatteras may be at

depth of five hundred fathoms

Thus, in a

—

of

80°,

Gulf

the

and at the

—

three thousand feet

as

actual observations show, the thermometer will stand at

Following the stream thence off the Capes of Vir-

5 7**. ginia,

one hundred and twenty miles,

the water-thermometer having been

the

way

—

that

it

surface, while all

now

it

will be

is

cooler.

found

carefully noted all

stands a degree or

below

59

replenished

is

,

s

§

two

less at

the

In other words, the

stratum of water at 57", which was three thousand feet

TemperatnreofGui/ stream.

34 caAPTER

THE PHYSICAL GEOGRAPHY OF THE

below the surface

off Hatteras,

has,

SEA.

in a course of one

hundred and twenty or one hundred and thirty miles

in

a horizontal direction, ascended, vertically, six hundred feet

;

that

is,

this

stratum has run up

hill Avith

an ascent

of five or six feet to the mile. §

As a

60

rule, the hottest

or near the surface is

sent down,

water of the Gulf Stream

at

and as the deep-sea thermometer

;

shows that these waters, though

it

is

still

far

warmer than the water on either side at corresponding depths, gradually become less and less warm until the bottom of the current lieve that the

warm

where permitted, bottom of the

is

lu

effect

There

sea.

climate of

Stream

Europe,

otherwise

is

in regions

to it

is

reason to be-

everywhere a cushion of

them and the

This arrangement

One

ingly beautiful

is

the oceanic economy, to touch the

in

cool water between earth's crust.

There

reached.

waters of the Gulf Stream are no-

is

solid

parts

suggestive,

of the

and

strik-

of the benign offices of the Gulf

convey heat from the Gulf of Mexico, where

would become

beyond the

excessive,

and

Atlantic, for the

to dispense

it

amelioration of

the climates of the British Islands and of aU Western

Europe,

Now,

tors of heat,

cold water

and

if

is

one of the best non-conduc-

warm water

the

of the Gulf Stream

was sent across the Atlantic in contact with the crust of the earth

—

heat

with a it

—

comparatively a good conductor of

instead of being sent across, as cool,

solid

it

is,

in contact

non-conducting cushion of cool water to fend

from the bottom,

all its

heat would be lost in the

fii'st

part of the way, and the soft climates of both France

and England would be

as tliat of Labrador, severe in the

extreme, and ice-bound.

•

INFLUENCE OF THE GULF STREAJM UPON CLL^UTES.

CHAPTER

85

II.

INFLUENCE OF THE GULF STREA3I UPON CLDtATES. How

—

the Climate of England

Atlantic, 65.

is regulated by it, § 61. Isothermal Lines of the —Deep-sea Temperatures under the Gulf Stream, 68. Currents

—

— Sea-nettles, 73. — Climates of the Sea, 75. — — Influence of the Gulf Stream upon the Meteorology of the of the Sea, — Furious Storms, 80. — Dampness of the English Climate due to the Ocean, — Influence upon Storms, — Wreck of the Steamer San Gulf Stream, Francisco, — Influence of the Gulf Stream upon Commerce and Navigation, 96. — Used for finding Longitude, 103. — Commerce in 1769, 106. indicated by the Fish, 70.

Offices

76.

78.

83.

85.

Its

88.

Modern

ingenuity has suggested a beautiful mode of warming bouses in winter. It is done by means of hot water. The furnace and the calib'on are sometimes •

chapteh

—

§ fil Principle

placed at a distance from the apartments to be warmed,

of heating

apparatus.

It

is

so at the Observatory.

to conduct

tlie

In

used

this case, pipes are

heated water from the caldron under the

superintendent's dwelling over into one of the basement

rooms of the Observatory, a distance of one hundred

feet.

These pipes are then flared out so as to present a large cooling surface again, through

of

its

own

turning

all

;

after

which they are united into one

which the water, being now

accord to the caldron.

Thus

cooled, returns

cool water

is

re-

the time and flowing in at the bottom of the

caldron, while hot water

is

continually flowing out at the

top.

The

ventilation of the Observatory

is

so arranged that

the circulation of the atmosphere through this pai-ts

basement room, where the pipes of the building

;

and

it

are,

is

led from

to all other

in the process of this circulation.

THE PHYSICAL GEOGRAPHY OF THE

36

SEA.

warmth conveyed by the water to the basement is taken thence by the air and distributed over all the rooms. Now, to compare small things with great, we

CHAPTER the

—

'-

warm

have, in the

waters which are confined in the Gulf

of Mexico, just such a heating apparatus for Great Britain,

the North Atlantic, and Western Europe. §

The furnace

62

is

the torrid zone

siTtioarity

Caribbean Sea are the

stream,

the conductiug pipe.

From

—

chamber

in

which

the

;

this

pipe

that the

is

—

the

flared out so as

is

Here the

arranged by nature

is

Banks of New-

the basement

is

to present a large cooling surface. of the atmosphere

Gulf Stream

the Grand

foundland to the shores of Europe hot-air

the Mexican Gulf and

;

caldrons

;

circulation

and

such,

it is

warmth thus conveyed into this warm-air chamis taken up by the genial west winds,

ber of mid-ocean

and dispensed, in the most benign manner, throughout Great Britain and the west of Europe.

The maximum temperature

§ 63

chamber of the Observatory

mum

is

of the water-heated air-

about 90°.

its

is 86**,

or about 9"

latitude.

Increasing

temperature of the Gulf Stream

above the ocean temperature due the latitude

1 0°, it losas

The maxi-

but 2° of temperature

;

and, after

having run three thousand miles toward the north, preserves, even in winter,

it still

With

the heat of summer.

this temperature, it crosses the

40th degree of north

lati-

tude,

and

itself

out for thousands of square leagues over the cold

there, overflowing its liquid banks, it spreads

waters aroimd, and covers the ocean with a mantle of Kffccf on

warmth that

climate,

rigours of wiutcr.

sei-ves

so

much

]\Io\ang

j)ensing its genial influences

to mitigate in

now more more

Europe the

slowly, but dis-

freely, it finally

meets

INFLUENCE OF THE GULF STREAil UPON CLIMATES. 37 the

By

British Islands.

these

it

is

divided/ one part coaptkr

going into the polar basin of Spitzbergen, of Biscay,

mense volume of heated water cannot beyond the

this it is

seas a mild

which

so

other

but each with a warmth

considerably above the ocean temperature.

it

the

Its CffGCt

Bay

entering the

much

Such an

fail to

ira-

on the theBritisii

carry with

and moist atmosphere.

And

softens climate there.

We know not, except approximately in one or two places,

§ (34

what the depth or the under temperature of the Gulf Stream may be; but assuming the temperature and velocity at the depth of two hundred fathoms

and taking the well-known

be those of the surface,

to

difference

caicuia-

between the capacity

of air and of water for specific heat as the argument,

a simple calculation will show that the quantity of heat dischargfed over the Atlantic

Stream

in a winter's day,

from the waters of the Gulf

would be

whole column of atmosphere that

sufficient to raise the

rests

upon France and

the British Islands from the freezing point to

summer

heat.

Every west wind that blows to

to

temper there

tlie

carries

Emerald

with

it

on

its west

a portion of this heat

northern winds of winter.

influence of this stream "

crosses the stream

winds

way

Europe, and

It

is

affected

the

upon climate that makes Erin the

Isle of the Sea,"

and that clothes the shores of

Albion in evergreen robes; while in the same latitude, on this side, the coasts of

of

ice.

yet

bound

in fetters Mr. Red-

paper on

was

who

fast

Newfound-

states that in

land,

Labrador are

In a valuable paper on currents,* Mr. Redfield

1831 the harbour

of St. John's,

closed with ice as late as the

month

of June;

ever heard of the port of Liverpool, on the other *

American Journal of Science, 1

Plate IX.

vol. xiv., p. 293.

38

THE PHYSICAL GEOGRAPHY OF THE

CHAPTER side, II.

though 2° farther north, being closed with

.

65

even

ice

.

in the §

SEA.

dead of ^vinte^

?

The Thermal Chart

(Plate IV.)

50°

shows

isothemiai lilies of the

thermal Hnes of

Atlantic,

parallel of 40** near the coasts of the off in

60",

&c.,

this.

starting ^

off

United

The

iso-

from the States, run

a north-eastwardly direction, showing the same

oceanic temperature on the European side of the Atlantic in latitude

55" or

in latitude

^O**.

60**,

we have on

that

the western side

Scott, in one of his beautiful novels,

tells

us that the ponds in the Orkneys (latitude near

are

not frozen in winter.

soft climate to this

The people there owe

grand heating apparatus,

from the West Indies

is

60**)

their

for diiftwood

occasionally cast ashore there

by

the Gulf Stream. §

66

Beneficial

Nor do

the beneficial influences of this stream upon

climate end here.

influence

The West Indian Ai'chipelago

compassed on one side by

on South

the other

climate,

.

.

of the

by the

en-

is

.

.

its

chain of islands, and on

Cordilleras of the Andes, contracting

with the Isthmus of Darien, and stretching themselves out over the plains of Central America and Mexico.

ginning on the summit of this range,

we

of perpetual snow, and descend

into the tierra

first

Be-

leave the regions tetiv-

plada, and then into the tierra caliente, or burning land.

Descending

still

surface of the

beautifid

lower,

Mexican

we

reach both the level and the

seas,

where, were

not for this

it

and benign system of aqueous

cu'culation, the

peculiar features of the suiTOunding country assm-e us

should have the hottest, climate in

the world

if

As

not

the

the waters

caldrons become heated, they are borne

Stream, and

ai-e

replaced

by

most

we

pestilential

these two by the Gulf

in

ofi*

cooler cm-rents through thft

-

:

INFLUENCE OF THE GULF STREAM UPON CLIMATES. Caribbean Sea

the surface water, as

;

3° or 4°, and that in depth

Taking only

escapes from the Gulf.

liere,

being

when

cuaj-tes

—

it

this difference in

temperature as an index of the heat accumulated

Eui'face

a simple calculation will show that the quantity

there,

of heat daily carried off

by the Gulf Stream from those

and discharged over

regions,

tlie

Atlantic,

is

sufficient to

mountains of iron from zero to the melting point,

raise

and

enters

it

40°* cooler than

39

keep in flow from them a molten stream of metal

to

greater in volume than the waters daily discharged from

Who,

the Mississippi River,

therefore can calculate the

benign influence of this wonderful cmrent upon the climate of the South

the

mind

nature fill

?

up

led from nature

is

and what mind

;

In the pursuit of this subject,

with profitable emotions

ing alone, of

emblem

of

its

Yea,

deep.

study of this subject not

Unchanged and unchang-

?

created things, the ocean

all

"

everlasting Creator.

the waves of the sea," and "

to the great Architect of

will the

He

is

He

is

the great

treadeth upon

seen in the wonders of the

calleth for its waters,

and pom-eth them

out upon the face of the earth."

In obedience to this planet preserves it

heat and

regions

land

;

;

its

warmth

the aqueous portion of our

call,

beautiful system of circulation.

are dispensed to the extra-tropical

clouds and rain are sent to

and by

it

By

refresh

the dry

cooling streams are brought from Polar

Seas to temper the heat of the torrid zone.

At

the

depth of two hundi-ed and forty fathoms, the temperature * Temperature of the Caribbean Sea (from the journals of Mr. Dunsterville) Surface temperature 83°, September 84°, July 83°-^S6^°, Mosquito Coast. :

Temperature

;

;

depth: 48°, 240 fathoms; 43°, 386 fathoms; 42°, 450 fathoms; 43°, 500 fathoms. in

«

gy

THE PHYSICAL GEOGRAPHY OF THE

40

SEA.

tlie Caribbean Sea has been found as low as 48°, while that of the surface was 85".

of the cm-rents setting into II.

Tempera-

with three hundi-ed and eighty-six fatlioms

ture of

Another

currents in the

gave 43° below against 83° at the surface.

Caribbean Sea.

The

hurri-

of those regions agitate the sea to great depths

canes

that of deep,

cast

1780

and

them

cast

;

up from the bottom seven fathoms

tore rocks

They

ashore.

therefore cannot

fail

to bring to the surface portions of the cooler water below.

At

§68 At the bottom of Gulf Stream.

the very bottom of the Gulf Stream,

was

face temperature

80°, the deep-sea

when

its sur-

thermometer of

the Coast Sm'vey has recorded a temperature as low as

35° Fahrenheit.

These cold waters doubtless come

§69 Within the

to replace the

warm water

down

fi'om the north

sent through the Gulf Stream

Arctic Circle.

to

moderate the cold of Spitzbergen

;

for within

the

Arctic Circle the temperature at corresponding depths off

the shores of that island

is

said to be only one degree

colder than in the Caribbean Sea, while on the coasts of Labrador and Polar

Labrador, and in the Polar Seas, the temperature of the

Seas.

water beneath the

De Haven Off coast

water

ice.

ice

was invariably found by Lieutenant

at 28°, or 4°

below the melting point of

Captain Scoresby

relates, that

fresh-

on the coast

of Greenland.

of Greenland, in latitude 72°, the temperature of the air

was 42°; of the water, 84°; and 29° surface current setting to the south,

centres, perhaps,

there found a

and bearing with

it

with vast numbers of icebergs,

this extremely cold water,

whose

at the depth of

He

one hundi-ed and eighteen fathoms.

were

far

below

zero.

It

would

be curious to ascertain the routes of these under currents on their

way

tended to

to the tropical regions,

cool.

One has

Ijeen

»

§23.

which they are

in-

found at the equator two

INFLUENCE OF THE GULF STREAil UPON CLIMATES.

41

hundred miles broad, and 23" colder than the surface Unless the land or shoals intervene,

water.

comes down in a

spiral

it

chapteh

—

no doubt

'-

curve, approaching in its course

the great circle route.

Perhaps the best indication as to these cold currents

may

be derived from the

first

pointed out the existence of the Gulf Stream by

avoiding

its

warm

fish

The whales

of the sea.

Along our own

waters.

§

70

currents byfisii.

coasts, all

those delicate animals and marine productions which delight in

warmer waters

are wanting; thus indicating,

by

their absence, the cold current from the north now known to exist there.

In the genial warmth of the sea about

the Bermudas on one hand, and Africa on the other, find in wreat

abundance

those delicate shell-fish

and

formations which are altogether wanting in the same

tudes alono" the shores

;

for there the

cold current almost reaches the line before the

of coral

A core

is

fii'st

sprig

found to grow.

few years ago, great numbers of bonita and

—

lati-

The same

of South Carolina.

obtains in the west coast of South America

we

coral

tropical fish

—

alber-

§

71

§

72

following the Gulf Stream, entered

the Encjlish Channel, and alarmed the fishermen of Corn-

wall and Devonshire

among It

by the havoc which they created

the pilchards there.

may

well be questioned

towns do not owe

if

our Atlantic

cities

and

their excellent fish-markets, as well as

our watering-places their refreshing sea-bathing in summer, to this stream of cold water. the Mediterranean ture of the

same

most part, very

is

4° or

latitude,

5°

above the ocean tempera-

and the

indifferent.

The temperature of

On

fish there are, for

the

the other hand, the teni-

THE PHYSICAL GEOGRAPHY OF THE

42

SEA.

below that

CHAPTER perature along our coast is several degrees

—

'-

of

the ocean, and from Maine to Florida our tables are sup-

most excellent of

plied with the so

much esteemed warm

flavour,

and

with other coast,

is

fish

;

coral

when taken

:

a

sheep's-head,

Carolinas,

banks of the Bahamas,

The same

held in no esteem.

they have

esteemed

and the

in Virginia

taken on the

The

fish.

in the cold

delicious

the case

water of that

and are highly

flavour,

but when taken in the

is

when

loses its

warm water on

the

other edge of the Gulf Stream, thouiih but a few miles unfit for the table.

The

temperature of the water at the Balize reaches 90".

The

distant, their flesh is soft, Effects of

and

tempe4'a-

ture on

taken there are not to be compared with those of the

fish

fiih.

same

her choicest current

Orleans, there-

to the cool waters on the Florida coasts for

fore, resorts

A

New

latitude in this cold stream.

The same

fish.

of

shores of Chili, Peru,

the

south sweeps the

and Columbia, and reaches the

pagos Islands under the distance, the

the case in the Pacific

is

cold water^ from

Throughout

line.

this

Galli-

whole

world does not afford a more abundant or

excellent supply of

Yet out

fish.

in the Pacific, at the

Society Islands, where coral abounds, and the water preserves a higher temperature, the

fish,

though they vie in

gorgeousness of colouring with the birds, and plants, and insects of the tropics, are held in

of food. still

I

have known

sailors,

to prefer their salt beef

taken there. this subject

The few seem

facts

no esteem as an

article

even after long voyages,

and pork

to a

mess of

fish

which we have bearing upon

to suggest it as a point of the inquiry

to be made, wliether the habitat of certain fish does not

indicate

tlie

temperature of the water, and whether these »

§455.

INFLUENCE OF THE GULF STREAM UPON CLIMATES,

43

and warm currents of the ocean do not constitute the

cold

great highways through

which migratory

from one region to another.

much

"VVliy

ohapteb

—

'-

fishes travel

should not

fish

be as

the creatures of climate as plants, or as birds, and

other animals of land, sea, and air

we know

Indeed,

?

that some kinds of fish are found only in certain climates.

In other words, they live where the temperatm-e of the

water ranges between certain degrees. Navigators have often met

young

They are known

Stream.

food for the whale

caused

with vast numbers

much

;

of

with the Gulf

sea-nettles {medusoi) drifting along

§

73

sea-nettiea

the principal

to constitute

but whither bound by this route has

speculation, for

is

it

well

known that the warm waters

habits of the right whale are averse to the

An

of this stream.

the Gulf Stream on the coast

of Florida, he feU in with such a " school of nettles as

had never before been heard

covered with them for

;

many

leagues.

sea

sea-

was

likened them,

but they were so thick as to completely cover

He was bound

the sea.

to England,

days in sailing through them. ward, on his return, he

in passing

them

again.

in with the

fell

He

and was

was

same school

off

three or four days

recognized them as the same,

he had never before seen any like them

occasions he

five or six Anecdott

In about sixty days after-

the Western Islands, and hei^e he

for

The

of,"

He

young

on the water, to acorns floating on a

in appearance

stream

me

informs

intelligent sea-captain

that, several years ago, in

;

and on both

frequently hauled up bucketfuls

and ex-

amined them.

Now, for

the Western Islands

whales

:

and

at first there

is tlie is

great place of resort

somethincr curious to ub

§

74

THE PHYSICAL GEOGRAPHY OF THE

44

CHAPTER in the idea that

—

'~

the Gulf of Mexico

SEA.

is

the harvest-field,

and the Gulf Stream the gleaner which

collects the fruit-

age planted there, and conveys

hungry whale at

to the is it

thousands of miles off

it

But how

sea.

perfectly in unison

with the kind and providential care of that great

and good Being which feeds the young ravens when they cry, §

75

ciimatesot the sea.

and caters

The

sparrow

for the

sea has

chauge with the latitude

botli

!

They

climates as well as the land.

its

but one varies with the

;

elevation above, the other with the depression below the

The

sea level. tion

;

climates in each are regulated

but the regulators

are,

by

circula-

on the one hand, winds

on

;

the other, currents. §

76

The inhabitants

much

of the ocean are as

of climate as are those of the dry land

Almighty hand which decked the sparrow,

fashioned also the

lily

pearl

the creatures

same

for the

;

and

cares for the

and feeds the great

whale, and adapted each to the physical conditions by

which

his providence has

land or the Offices of

sea,

sea,

therefore,

we may

duties to perform

and

so, too, its

takes to stvidy

exquisite

;

so,

its

in

has

;

infer,

economy. its

have

consequently, he

phenomena must

He must

of

offices

its

it

The and

currents,

who under-

cease to regard

look upon

tlie

his creatures,

all

his

safely infer,

may we

inhabitants

a waste of waters. that

and agents

Whether

it.

inhabitants are

the

subjects of his laws,

surrounded

it

as

as a part of

machinery by which the harmonies of

nature are preserved, and then he will begin to perceive the developments of order tliese

make

it

contemplation.

and the evidences of design

;

a most beautiful and interesting subject for

—

^

;;

INFLUENCE OF THE GULF STREAM! UPON CLIMATES.

45

To one who has never studied the mechanism watch,

main-spring or the balance-wheel

its

He may

metal

piece of

it

wondered

keeps, or the

in idle

machinery which

time

amazement is

of a chapter

it

plays,

its

hands, and

he

may have

^

as to the character of the

Take

concealed within.

and show him each part

—

a mere

have looked at the face of the

watch, and, while he admires the motion of the time

is

it

to pieces,

he will recognize

separately,

neither design, nor adaptation, nor relation between

them

but put them together, set them to work, point out the offices of

each spring, wheel, and cog, explain their move-

ments, and then show him the result; that

it is all

now he

ber of parts, their diverse forms and various the agents concerned, the whole piece

He now

the expression of one idea.

when

perceives

one design; that, notwithstanding the num-

•

is

offices,

of one thought,

rightly concludes that

/•I'll

•

1

the main-spring was fashioned and tempered,

relation to all the other parts

and

•

its

must have been considered cut and regulated

that the cogs on this wheel are

adapted

—

to the rachets

on

that, &c.

clusion will be, that such a piece of

have been produced by chance; parts

is

such as to show

it

;

and

his final con-

mechanism could not

for the adaptation of the

to be according to design,

obedient to the will of one intelligence.

So, too,

and

when

one looks out upon the face of this beautiful world, he

may admire

its

lovely scenery, but his admiration can

never grow into adoration unless he will take the trouble to look behind

and study,

in

some

of its details at least,

by which such beautiTo him who does this,

the exquisite system of machinery ful results are

brought about.

the sea, with

physical geography, becomes as the main-

its

Reflec-

l'on&

— 46

THE PHYSICAL GEOGRAPHY OF THE

CHAPTER spring of a salts,

and

watch;

and

its

cuiTents,

and

its

with their adaptations, as balance-

its inliabitants,

wheels, cogs

and

its watei-s,

SEA.

pinions,

and

Thus he perceives

jewels.

that they, too, are according to design; that they are the

expression of

One Thought, a unity with harmonies which and One Intelligence alone, could utter.

One

Intelligence,

A.nd

when he has

arrived at this point, then he feels that

the study of the sea, in It elevates the

blime.

Gulf Stream

now no

is

its

physical aspect,

truly su-

is

mind and ennobles the man.

by such an one merely

The

longer, therefore, to be regarded

as an

immense current of warm

water running across the ocean, but as a balance-wheel a part of that grand machinery by which air and water are adapted to each other, and is

by which

adapted to the well-being of

flora

which decks, and the

its

this earth itself

inhabitants

fauna which

—

of the

enlivens

its

surface. §

Let us

78

Influence of the Gulf

stieam on the meteoroiogyof

now

consider the influence of the Gulf Stream

upon the meteorology of the ocean. To use a saiior expression, the Gulf Stream "

1

1

,

wcather breeder

most clurious gales •

i

fogs of

gation

,,

c

t

•

^

the sjreat

•

^

wind sweep along vnih

oi

The

•

it;

and the

Newfoundland, which so much endanger naviin winter,

owe their existence to the of immense volumes of warm

doubtless

presence, in that cold sea,

water brought by the Gulf Stream. found the air on each side of while that of

damp

is

«

of the North Atlantic Ocean.

air

its

it

waters was 80*

Sir Philip .Brooke

at the freezing point, "

The heavy, warm,

over the current produced great irregularities

in his chronometers."

into such a region

The excess of heat

daily brouglit

by the waters of the Gulf Stream

INFLUENCE OF THE GFLF would,

make

STREA:^!

UPON CLDIATES.

suddenly stricken from them, be

if

47

sufficient to ohaptkk

than melted

bosom,

we might

kind to accompany

most

terrific

in its com-se.

it

nautical

works

and piled up the water

Gulf to the height of thirty

attempted to ride

to

it

high up on the diy land, and discovered that she had

let

go her anchor among the tree-tops on

The Florida Keys were inundated many

§

gj

Key.

Elliott's

feet; and, it is

the scene presented in the Gulf Stream was never

sm-passed in awful sublimity on the oceaa

thus

gQ

abated, she found her-

self

said,

§

in the

The Ledbury Snow

feet.

When

it out.

known

borders.

its

us of a stomi which forced this

tell

its sources,

itsiiabiiitT

Accordingly, the

that rage on the ocean have been

stream back to

in § 79

expect stonns of the most violent

spend their fury within or near

Our

1-

iron.

With such an element of atmospherical disturbance its

—

the column of superincumbent atmosphere hotter

dammed up

The water wonder-

said to have rushed out with

is

ful velocity against the fury of the gale,

producing a sea

that beggared description.

The "great hurricane" of 1780 commenced at Barbadoes.

In

it

was blown from the

the bark

the fruits of the earth destroyed

trees,

and

the very bottom and

;

depths of the sea were uprooted, and the waves rose to such a height that forts and castles were washed away,

and

their great

guns carried about in the air like chaff;

houses were razed,

men and in

aliips

beasts lifted

the storm.

At

were wrecked, and the bodies of

up

the

twenty thousand persons

in the air different

and dashed to pieces

islands,

lost their lives

farther to the north, the " Stirling Castle"

not

less

on shore

and the

;

"

than while

Dover

Great har-

17^"*

°

THE PHYSICAL GEOGRAPHY OF THE

48

men-of-war went down at

CHAPTER Castle"

sea,

and

SEA. fifty sail

were

driven on shore at the Bermndas. 82

Several years ago, the British Admiralty set on foot

Admiralty

as to the cause of the storms in certain parts inquiries ^ ^

§ British

investiga-

of the Atlantic, which so often rage with difistrous effects

ton.

The

to navigation.

may

result

summed up

be

conclusion to which the investigation led

by the

occasioned

in-egularity

in the

that they are

:

between the temperature

of the Gulf Stream and of the neighbouring regions, both

and water. The habitual dampness

in the air

83

§

Dampness of English

wcU

jgi^nds, as '

of the climate of the British

of that alonfj as the occasional dampness ^

§ 124.

«

§ 149,

'

§ 144.

THE PHYSICAL GEOGRAPHY OF THE

78 en A PIER of

the sun to create a polar and equatorial flow of

were Bi.n

on the

its

power confined simply

to a

which increases

stances

sun

air.

But

change of level

still

its

more power

mobility, to put

and gives the heat of the

it

in motion,

as heat changes the atmospherical level,

'

air,

the atmosphere has been invested with another property

supposed

Specific

SEA.

and it

the specific gravity of the air acted upon.

it

is

this

therefore,

If,

the level of the great aerial ocean were undisturbed

the sun's rays, and

if

:

changes aLso

by

the air were adapted to a change

of specific gravity alone, without any change in volume, this quality

would

also

be the source of at least two

systems of cmrents in the lower.

air,

namely, an upper and a

The two agents combined, namely, that which

changes level or volume, and that which changes gra\-ity, give

specific

us the general currents under consideration.

Hence we say that the priTnum mobile

of the air

is

derived from change of specific gravity induced by the freezing temperature of the polar regions, as well as from

change of

specific gravity

due the expanding force of the

sun's rays within the tropics. §

154

Con-

Therefore, fairly to appreciate the extent of the influence

due the heat of the sun in causing the winds,

it

should be

elusions. _

recollected that

we may with

as

much

reason ascribe to

the inter-tiopical heat of the sun the north-west winds,

which are the

jirevailing

winds of the

regions of the southern hemisphere,

extra-tropical

or the

south-west

winds, which are the prevailing winds of the extra-tropical regions of the northern hemisphere, as

we may

winds, whicli blow in the o[)posite directions. cal, therefore,

the trade-

Paradoxi-

as it seems for us to say that the heat of

the sun causes the winds between the parallels of 25' or

THE ATMOSPHERE.

79

80° north and south to blow toward the equator, and chapteb III.

that

it also

causes the prevaihng winds on the polar sides

of these same parallels to blow toward the poles,

j^et

the

paradox ceases when we come to recollect that by the process of equatorial heating

and polar cooling which

is

going on in the atmosphere, the specific gravity of the air is

as well as changed '^

Nevertheless, as Halley

its level.

_

said, in his

in

paper read before the Royal

1686, and as we also have

hard to conceive

why

said,^ " it is

London

Hkewise very

the limits of the trade-wind should

be fixed about the parallel of latitude 80° globe,

Haiieys veuiuiks.

_

Society in

all

around the

and that they should so seldom exceed or

fall

short

of those bounds."

Operated upon by the equilibrating tendency of the

§ 1,55

atmosphere and by diurnal rotation, the wind approaches How the north pole, for example, by a series of spirals from the south-west.

common

If

•

we draw

11about

a circle

ten'estrial globe,

and

intersect it

represent the du-ection of the wind,

wind enters and

all

this

that, consequently, there

calm

by

on a

as wind,

and

disc, therefore,

shall see that the

should be about the poles a

which the

air ceases to

ascends as in a calm

;

about

there should be a whirl, in which

At

or against the hands of a watch.

left,

the south pole the

winds come from the north-west,^ and consequently there they revolve about

it

udth the hands of a watch.

this should be so will be obvious to

will look at the arrows

Cancer and

poie.

spirals to

the ascending column of air revolves from right to

That

proachea nortli

1

parts of this circle from the south-west,

disc or circular space of calms, in

move forward

we

•

1

this pole

Capricorn *

any one who

on the polar sides of the calms (Plate

§ loo.

I.)

«

§ 137.

These

arrows are

&Jui!ipoid

THE PHYSICAL GEOGRAPHY OF THE

80 CHAPTER

—

'-

§

intended to represent the prevailing direction of the wind at the sm-face of the earth on the polar side of these calms.

between these two

It is a singular coincidence

156

Singular

SEA.

and other

tlius dcduccd,

facts

which have been observed

facts

foincid-

by

Bedfield, Reid, Pidding-

ence re-

and which have been

rotatoiy

ton,

whirl-

in the northern hemisphere revolve as do the whirlwinds

and

set forth

namely, that

others,

about the north

pole,

all circular gales in

many

of the rotatory storms

namely, from right to

left,

and that

the southern hemisphere revolve in the

opposite direction, as does the whirl about the south pole. §

How

157

can there be any connection between the rotary

motion of the wind about the of §

158

That there

pole,

by

in a gale caused here

it

and the rotary motion

local agents

?

probably such a connection has been

is

suggested by other facts and circumstances, and perhaps I shall

be enabled to

treat

of these

farther^ into Heat not

make myself

facts

when we come

clearer

and circumstances, and

to

to

inquire

the relations between magnetism and the

circulation of the atmosphere

for,

;

although the theory

the sole

sKcntof

of heat satisfies the conditions of the problem,

winds.

f

.

heat, doubtless,

is

^

'

^

the circulation of the atmosphere, yet

appear that §

159

Offices of

Some of see

how

the atmosphere moves

;

.

to perform,

alluded to

time, to consider sea,

;

keeping up

—So

far,

,

oi

and they are many.

some of them

1

we

but the atmosphere, like

every other department in the economy offices

and though

can be made to

Meteorological Agencies.

the atmo-

jphere

it

not the sole agent.

it is

its

m •

(>

one of the chief agents

but

I

.

nature, has its I

liave already

only propose, at this

some of the meteorological agencies

at

which, in the grand design of creation, have probably

been assigned to

this

wonderful machine. 1

As

at §299.

L

THE ATMOSPHERE.

To and

81

distribute moistiu'e over the surface of

temper the climate of different

to

by J

offices assicmed seem, are two great b o the ocean and the air. '

earth, chapteb

tlie

latitudes, it

—

would

their Creator to

,

.

On moistureand climate.

When

the north-east and south-east trades meet and

produce the equatorial calms,^ the reaches this calm belt,

hemisphere

in each

upward

direction.^

a portion of

;

§

ipi

it constant

heavily laden with moisture, for

is

tionin

no room for escape but in the

It has

cooler

by the time

has travelled obliquely over a large

it

space of the ocean.

air,

It

expands as vapour

its

comes down in the shape of

and becomes

it

ascends,

is

thus condensed, and

Therefore

rain.

it

is

that,

under these calms, we have a region of constant precipita-

Old

tion.

such dead calms of long con-

sailors tell us of

Singii:ar fact.

tmuance

here, of such

heavy and constant

have scooped up fresh water from the sm'face of the

The conditions

which

to

this air is

the moisture that

it

sea.

exposed here under

the equator are probably not such as to cause ])itate all

they

rains, that

it

has taken up in

its

Let us see what becomes of the

for Natui-e, in her

economy, permits nothing to be

;

taken away from the earth which to

is

162

§

1

long

sweep across the waters. rest

§

to preci-

not to be restored

again in some form, and at some time or other.

it

Consider the sippi,

gi-eat rivers

We

the

Amazon and

the Missis-

them day after day, and discharging immense volumes of water

for example.

year after year,

—

see

03

Amazon '^

sipU

into the ocean.

"AH (Eccl.

i.

the livers run into the sea, yet the sea 7).

Where do

where do they come from

you

will say.

?

They come from

But whence are »

is

not full"

the waters so discharged go, and

§ 135.

their sources,

their sources supplied

»

§ 136.

?

for,

whenr.o sources

^"^^

'^

'^

THE PHYSICAL GEOGRAPHY OF THE

82

what the fountain senda

CHAPTER unless

—

-

§

again,

1

164

precipita-

it

We

will fail

and be

SEA.

forth be returned to

by

see simply, in the waters that are discharged

thcse rivers, the

it

diy.

amount by which the

precipitation exceeds

Hon exceeds evapoiation.

the evaporation throughout the whole extent of valley

,•••,,

drained by them

amount

...-rI

ii

;

of water that falls from, or

atmosphere, whether as dew, rain, §

165

The

is

the total

deposited by the

hail, or

snow.

springs of these rivers^ are supplied from the rains

of heaven,

and these

are taken

up from the

rains are formed of vapours sea,

that "

it

be not

earned up to the mountains through the "

mean

and by precipitation

Note the place whence the

which

full,"

and

air,

rivers come, thither they

retiu'n again." §

1

(36

Waters

nf

Behold the St.

how the waters

Lawrcucc, and

of the

ia'tpi

rivers car-

and Asia,

Amazon, of the

Mississippi,

the great rivers of America,

all

ii

i

i

up by the atmosphere, and

riedback

Luropc,

sources,

flowiug in invisible streams back through the air to their sources

among

lifted

the

hills,"

and that tlirough channels

so

regular, certain, and well defined, that the quantity thus

conveyed one year with the other for that is the

quantity which

the ocean through

tliese rivers

annually by each river

is,

;

we

is

see

nearly the same

:

running down to

and the quantity discharged

as far as

we can

judge, nearly

a constant. §

167

Order and

We now ^

in

of^tmo-

;

and, though

it is

apparently so

'^

arrange-

ment

begin to conceive what' a powerful machine

the atmospheve must be capricious

and wayward

of order and pi'oof

_

in

_

its

movements, here

evidence

arrangement which we must admit, and

which we ainnot deny, that

office Avith

is

regularity

*

and § 112.

it

performs this mighty

certainty,

«

§ 112.

and

is,

therefore, as

THE ATMOSPHERE. law as

o1>edient to

is

83

the steam-engine to the will of

its chapter

builder.

L

It, too, is

all their

an engine.

The South Seas themselves,

in § 168

vast inter-tropical extent, are the boiler for

and the northern hemisphere

is

condenser.

its

it,

Comparison with

The

thestenai Gil trine

mechanical power exerted by the air and the sun in ing water from the earth, in transporting place to another,

and

in letting

ceivably great.

The

utilitarian

power that the to machinery,

astonished

is

which are required

Yet what steps, in

to

lift

is

at the

incon-

water-

afford if applied

number

of figures

to express its equivalent in horse-power.

the horse-power of the Niagara, falling a few

and

as high as the clouds

the water that river,

would

comparison with the horse-power that

up

from one

it

it down again, is who compares the

Falls of Niagara

lift-

is

but by

let

is

required

down again

all

discharged into the sea, not only by this other rivers in

all

The

the world.

cal-

made by engineers, and, according to it, making and lifting vapour from each area of

Caicuia-

dilation has been

force re-

the force for

lifting va-

one acre that

is

included on the surface of the earth

is

me

earth,

equal to the power of 80 horses, and for the whole area of the earth

power

it

is

800 times

greater than

vapour

makes

all

the water-

in Europe.

Where does

the

that

the rains ivhich § 169

feed the rivers of the northern hemisphere come

from

?

The proportion between the land and water in the

Difference propor-

.of

northern hemisphere

is

that obtains between

very different from the proportion

them

m

the

southern.

In the

tion be-

tween land anu water

northern hemisphere, the land and water are nearly equally em divided.

In the southern, there

water than land.

is

several times

more

All the great rivers in the world are

and

he tiemi'^'®"'^-

—

;

THE PHYSICAL GEOGRAPHY OF THE

84 CHAPTER in the '-

northern hemisphere, where there

Whence, then, are

supply them. Tliose of the

River

Amazon

equatorial calms

and trade-winds of the

mark.

always near

both hemispheres,

and as

line,

tributaries

its

supplied with water

high-water

Amazou,

only great

is

Boutheni

no large river in

made

of vapour

Taking the

sphere,

give rise to none, nor

the ouly gi'eat river of the southern hemisphere.

New

is

and

rivers of

we know

of

North America and North

the northern hemisphere.

How

that the evaporating surface is

it,

is

there one in South Africa entitled

the rivers of Europe and Asia,

hemisphere —how

There

The South Sea Islands

Holland.

to be called great that

all

It dis-

come from

out of the count, the Rio de la Plata

Riodeia

therefore,

its

northern tributaries

taken up from the Atlantic Ocean.

'^^16 gi'eat

;

it

cannot be said to belong exclusively

it

It is

to either.

its

southern for the other half

its

charges under the

is

It is

For one half of the year

are flooded, and

170

That

Atlantic.

come from the north and south

a river without periodic stages of a

it is

very marked character.

§

ocean to

always the rainy season on one side or the other of

consequently,

that

is less

their sources replenished?

are supplied with rains from the

river runs east, its branches it is

SEA.

I

lies

is

it,

lie

then, considering

mainly

say, that

we

Africa,

wholly within

in the southern

should have the

evaporation to take place in one hemisphere and the con-

The

Greater

densation in the other

rX^faiia"

falls in the northern hemisphere

?

which

amount of rain which much gi-eater, meteorol-

total is

the southern.

Tlie

ern"hemi-

ogists tell US, than that

southeri^"

annual amount of rain in the north temperate zone half as

5

171

much

How is

it,

falls in

is

again as that of the south temperate. then, that this vapour gets, as stated,^ from

§170.

tlie

THE ATMOSPHERE.

85

southern into the northern hemisphere, and comes with chapteb

—

such regularity that om* rivers never go diy and our springs

not

fail

and the

compensation of

exq\iisite

the atmosphere.

It

winter,

and

in early spring, the

\vith the greatest intensity

southem hemisphere, and

sun

is

down upon

tnis

pouring his rays

gphe°re

the seas of the

the^ionu-

we

f™mVh"

powerful engine which

pumping up the water there^ for our with the greatest activity. At this time, the mean

are contemplating rivers

and wonderfully coun-

exquisitely

is

giund machine,

this

Late in the autumn of the north, throughout how the

terpoised. its

-

It is because of the beautiful operations

?

is

temperatm'e of the entire southern hemisphere

jp^g''""

said to

is

be about 10° higher than the northern.

The heat which latent,

this

heavy evaporation absorbs becomes

and, with the moisture,

upper regions of the atmosphere mi til

Here the vapoui' state of it is

vapour

is

It clouds

172

reaches our climates.

formed into clouds, condensed, and

set free, it

that which contributes so

climate.

we

is

it

The heat which held

precipitated.

§

earned through the

is

up

water in the

this

becomes sensible heat, and

much

to

in winter, turns

are going to have falling weather.

temper

oiu*

winter

warm, and we say That

because

is

Processor coiidensa-

the

process

of

condensation

this southern heat that has

of the sun

m

by the

sea,

has

may have

though no rain or snow

already fallen

:

commenced, thus

we

tion.

feel

been collected from the rays

been bottled away by the winds

the clouds of a southern summer, and set free in the

process of condensation in our northern winter. If Plate

I.

fairly represent the course

the south-east trade- winds sphere, and, as

an upper

of the

current, bear into

_^^____________ ^

winds,

woidd enter the northern hemi-

§ 169.

it

all

their

§

173

trade-"^^'

thTir^moi" ture into northern

hemi•Inhere.

THE PHYSICAL GEOGRAPHY OF THE

86

CEAPTER moisture, except that

which

SEA.

precipitated in the region of

is

in.

equatorial calms. §

The South

174

Hypo-

^

thesis.

it

;

mainly the water

Seas, then,^ should supply

noiihem hemisphere condenses

for this enoine, while the

\

' .

we

have more rain in the northern

should, therefore,

The

liemisphere.

on the land

we have

rivers tell us that

—

at least

for the great water-courses of the globe,

:

and

half the fresh water in the world, are foimd on our side

This fact alone

of the equator.

strongly corroborative

is

of this hypothesis. §

The rain gauge

175

tells

The

us also the same story.

Confirmed fy rain

yearly average of rain in the north temperate zone

gauge.

according to Johnston, thirty-seven inches.

.

,

•

tt

gives

The observations

but twenty-six in the south temperate.

Log-

of mariners are also corroborative of the same.

upward of

books, containing altogether the records for

260,000 d&js

examination of log-

gales,

therein recorded

number

for the north

than

examination

is

.

of each

it is

northern hemisphere, ^vith southern, with

its

its

shows the status

it

unstable

in

Rains, and fogs,

and storms,

their occurrence

result of this

the

excess of land, than in the

all

and are more irregular

and place of

The

much more

excess of water.

thunder, and calms, frequently,

•

for the south.

be

and

Propori i n given as decidedly greater .

is

very instructive, for

of the atmosphere to

of calms, rains,

each hemisphere.

for

,

tionally the

south,^

for the purpose of ascer-

number

taining, for comparison, the Result of

Ocean north and

in the Atlantic

have been carefully examined

is,

•

He

i

on

occur

also

as to the

this side,

and

much more time

than they are

on the other side of the equator. §

17G

Moisture

is

1

never extracted from the According to

§ 16S.

«

aii*

by subjecting

Plate XIII.

87

THE ATMOSPHERE. it

from a low to a higher temperature, but the

Thus

all

reverse, chaptek

—

the air which comes loaded with moistm-e from T

the other hemisphere, and

1

•

•

•

ii

I

-ii

i_i

borne into this witli tbe

is

south-east trade-winds, travels in the upper regions of the

atmosphere^ until

it

reaches the calms of Cancer

here

;

'-

Moisture never essubjecting

it frmn a

becomes the surface wind that prevails from the south-

ward and westward. As it goes north it grows cooler, and the process of condensation commences. We may now liken it to the wet sponge, and the

i.a»

tempefl-'" '"'''•

§

177

decrease of temperature to the hand that squeezes that

Finally reaching the cold latitudes, all the mois-

sponge.

ture that a dew-point of zero, and even far below, can

from

extract, is wi'ung

it

" to return according to

And

here

wmd

1

we

•

dnveth away ram.

dry atmosphere.

hib circuits" as

nil

>>

commences

this air then

quote Scii]tture again

can

1

•

and

;

•

Ihis

:

The

"

•

is

nortli 1

•

1

/•

a meteorological tact

imr)-.onto suppose that the

south-east trade-winds,

^^^®

when they

and ascend,

calms Q^ equatorial ^

is,

ia

that

arrive at the belt

and continue

cross over

trade-

their course as

crossatthe

while the air that the north-east trade-winds discharge

calm

an upper

ciu-rent to

the calms of Cancer,

belts.

into the equatorial calm belt continues to go south, as

upper current bound for the calms of Capricorn.

what should cause

this

wind

to cross over

an

But

Why should

?

there not be a general mingling in this calm belt of the air

why

brought by the two trade-winds, and

should not

that which the south-east winds convey there be its ascent, to

302

In the

after

flow off either to the north or to the south,

as chance directs §

left,

?

was

first place, it

the grand design

;

my

at variance with

for I could not bring

faith in

myself to believe

that the operations of such an important machine as the

atmosphere should be

Yet

I

knew

chance, even for a moment.

left to

of no agent which should guide the

across these calm belts,

and lead

side opposite to that on

which

certain circumstances

seemed

it

wind

out always on the

it

entered

;

nevertheless,

to indicate that such a cross-

ing does take place. §

303

iivifience ill

Evidence in favour of

seemed

be afforded by this

to

circumstancc, namely, our researches enabled us to trace

favour

of tins sup-

it

n

-i

1

1

• .

from the belt of calms, near the tropic extends entirely across the

seas,

an

y^

j^

efflux

•

i

Lancer, which

oi

i

of air both to

the north and to the south; from the south side of this belt the air flows in a never-ceasing breeze,

north-east trade-winds, toward the equator.

On

the north side of

it,

called the

(Plate

I.)

the prevailing winds come

1

MAGNETISM AND CIRCULATION OF THE ATMOSPHERE. from

They

but they go toward the north-east.

it also,

137 chaptek

—

are the well-known south-westerly winds which prevail

.

along the route from this countiy to England, in the ratio

But why should we suppose a crossing

of two to one.

to

take place here?

We fToino-

suppose

because these last-named winds are

so,

from a warmer to a colder climate, and therefore

may be inferred that know she exacts from but on a smaller

natm-e exacts from them what

§

304

§

305

it

we

the air under similar circumstances,

scale, before oui- eyes,

namely, more pre-

cipitation than evaporation.

But where,

it

may

be asked, does the vapour which

these winds carry along, for the replenishing of the whole whence extra- tropical regions of the north,

m

They did

come from?

.

came along

comes the vapour for replenish-

.

the upper regions, a

ingtiie ex-

counter-current to the north-east trades, unless they eva-

cai regions

not get

it

as they

porated the trade-wind clouds, and so robbed those winds of their vapour.

They

certainly did not get

from the

it

sm-face of the sea in the calm belt of Cancer, for they did

not tarry long enough there to become saturated with moisture.

Thus circumstances again pointed

to the south-

east trade-wind regions as the place of supply.

Moreover, these researches afforded grounds for the §306 supposition that the air of which the north-east trade- North-east ^ .

trade-

,

winds are composed, and which comes out of the same 1

.

1

/>

zone of calms as do these south-westerly winds, so tar

from being saturated with vapour at for

its

exodus,

is

near their polar edge, the north-east trade vnnds

for the

most

part,

dry winds.

dry; are,

Reason suggests, and phi-

losophy teaches, that, going from a lower to a higher temperature, the evaporating powers of these winds are

winds for *''

•

1

1

which

01

•

this

Region of precipitatiou.

considering as

impinges, ought to be a region of copious

first

precipitation.

Now, and

let

us turn to the works on Physical Geography,

what we can

see

and Johnston

find

upon

—department

In Berghaus

this subject.

Hyetography

—

it

is

§

344

Patagonia.

stated,

on the authority of Captain King, R. N., that upward of twelve feet (one hundred and

fifty- three inches)

of rain

fell

in forty-one days on that part of the coast of Patagonia

which

lies

within the sweep of the winds just described.

So much rain

falls there,

navigators say, that they some-

times find the water on the top of the sea fresh and sweet.

After impinging upon the cold hill-tops of the Pata-

gonian

coast,

and passing the snow-clad summits of the •

111down

1

Andes, this same wind tumbles slopes of the range as a dry

wind

upon the eastern

as such,

;

the almost rainless and barren regions of

cis-

it

§

345

Becomes a '^^ wind in Buenos

traverses

Andean Pata-

gonia and South Buenos Ayres.

These conditions, the direction of the prevailing winds,

and the amount of

precipitation,

may

be regarded as evi-

§

346

Evidence in favour

deuce afforded by nature, against,

if

not in favour

the conjecture that such

voyage of

this

may

vapour through the

air.

of,

certainly not

have been the

At any

rate,

of conjeo-

;

THE PHYSICAL GEOGRAPHY OF THE

150

immense quantity

CHAPTER here is proof of the

—

'-

SEA.

of vapour which

these winds of the extra-tropical regions carry along with

them toward the

poles

and

;

I

can imagine no other place

than that suggested, whence these winds could get so

much Theory.

I

vapour.

am

not Unaware of the theory, or of the weight

attached to

which requires precipitation to take place

it,

upper regions of the atmosphere on account of the

in the

cold there, irrespective of proximity to

snow-clad §

347

mountain tops

an(l

hills.

But the

and conditions developed by

facts

Facts irre-

of research upon the high seas are in

abie with

concileable with that theory.

many

this

system

respects irre-

With a new system

of facts

before me, I have, independent of all preconceived notions

and tions §

How

348 do

the currents of

opinions, set about to seek

and

These

for explana-

reconciliations.

may

not in

all cases

indeed, notwithstandincr o the '

be satisfactory to every one

amount

of circumstantial evi-

dcucc that has already been brought to show that the air "^

air cross

each other

among them

which

the

'-'

and the south-east trade-winds,

north-east

discharge into

the

ascending,

—

cross

belts

I.)

question, "

other?"

—

does,

in

and that from the northern passing

over into the southern hemisphere (see C, Plate

calms,

from the southern passing over

that

into the northern,

of equatorial

F

and G,

B and

yet some have implied doubt by asking the

How

And,

are

two such currents of

for the

want

of light

air to pass

upon

correctness of reasoning, facts, inferences,

each

this point, the

and deductions

have been questioned. §

349

tiUmbeJt!

In the equatorial

first

place, it

calms

is

may

be said in reply, the belt of

often several hundred miles across,

1

MAGNETISM AND CIRCULATION OF THE ATMOSPHERE. 151 seldom

than sixty

less

whereas the depth of the volume

;

chapter VI.

of air that the trade-winds pour into miles, for that

it is

only about three

supposed to be about the height to which

is

of tia-

Heat does not

most complete of non-conductors. it

demon

ice.

*'

meate water as

and flora ofthesia as depen-

capacities for heat are scarcely § 399

its

•'

393

The fauna

and the habitat

exceeded by those of any other substance,

conductors.

The polar

§

under the iceberg, or in

waters colder than the melting

Now

proclaims

out

the whales of the sea

inhabitants proclaim

all its

it

chapteh YH.

and that at the bottom remains

p«s

cool.

The heat passes through iron by conduction, but to get it requires to be conveyed by a motion,

through water

which

in fluids

we

call currents.

Therefore the study of the climates of the sea involves

a knowledge of

its currents,

both cold and warm.

They and

§

400

ledgeofit?

are the channels throucrh which the waters circulate,

necessary

by means

[n'„f"f^'

of which the harmonies of old ocean are pre-

''

served.

f^""'"'''

Hence, in studj'ing the system of oceanic circulation. '

§ TO.

M

T6

§

40I

THE PHYSICAL GEOGRAPHY OF THE

168 CHAPTER

—

we

set out

SEA.

with the very simple assumption, namely, that

VII

'-

from whatever part of the ocean a current

tion on

based the

to retm'u; for

cunents.

tlie

is

same part a current of equal volume

run, to

found to

bound

is

upon this principle is based the whole systcm of Currents and counter-currents of the air as well as of the water.

Currents of water, like currents of

402

§

v.'iiiri-

meeting from

air,

various directions, create gyrations, which in some parts

pools.

of the sea, as on the coast of

Norway, assume the appear-

ance of whirlpools, as though the water were drawn into

a chasm below. a

such

Beechey,

conflict E-.N.,*

The celebrated Maelstrom of

or other

tidal

is

caused by

Admiral

streams.

many

has given diagrams illustrative of

liotatory

" rotatory

En-iish CiuuuieL

which occur between the outer extremities of the channel

streams in the English Channel, a number of

and the stream of the oceanic or parent wave."

tide

are clearly to be accounted for," says he, "

"

They

by the streams

acting obliquely upon each other." §

403

Currents of the sea

can ran up

It is not necessary to associate with oceanic cuiTents

^^^

-^^gg^ ^j^g^^

«'

g^

stTOim

§

404

Those runiiing hito file .Seii

Rid and

Meditcrranean are the reverse

So

hiffher to a lower level.

case,

Z"' these.

Qj^jg^, of neccssitv, as ^^x^y •^

far

'

on land, run from

from

'

this

some currents of the sea actually run up

being the hill,

while

others inin on a level.

The Gulf Stream is of the first class.' The currents which run from the Atlantic into the MeditciTancan, and from the Indian Ocean into the Red Here the bottom of the curSea, are the reverse of this. rent is probably a water-level, and the top an inclined Take the Red Sea current as plane, running down hill. .

* See Eii;;lish

,

.

f^,

an interesting paper by hlin on Tidal Streams of the North Sea and Phil. Transactions, Part ii., 1351. i>\>. 703;

Channel.

I

S Q

-

CURRENTS OF THE an

That sea

illustration.

a rainless and rlverless

thus taken up It is

is

It

district.

it

most

may

m

Being

a long and narrow trough. the evaporation from

for the

lies,

169

SEA. part,

within chaptkr

—

VII.

be compared to

a rainless

-

district,

immense; none of the water

is

retui-ned to

either

it

about one thousand miles long;

by

rivers or rains.

nearly north

it lies

itssizeand latitude.

and south, and extends from latitude 13° to the parallel of 30° north.

From May

to October, the water in the upper part of

this sea is said to be

two

lower than

feet

it is

near the

§

405

Difference of level

This change or difference of level

mouth.*

ascribed to

is

m

"•

the effect of the wind, which, prevailing from the north at that season,

is

supposed to blow the water out.

But from May the season

when

to October

evaporation

is is

also the hot season; it is

going on most rapidly;

and when we consider how dry and how hot the winds are which

blow upon

we may suppose not

less,

certainly,

that amount.

§

406

immense '"•

this sea at this season of the year,

the daily evaporation to be immense;

than half an inch, and probably twice

We know

that the waste from canals

by

summer time, when taking the capacity of his feeders into With him it is an important calculation, has to consider. how element; much more so must the waste by evaporation from this sea be, when we consider the physical con-

evaporation, in the

is

an element which

the engineer,

ditions under

Sea, is

which

it is

Its feeder, the

placed.

a thousand miles from

burning sands; the evaporation

its is

head;

its

ceaseless;

the vapours, which the scorching winds that

carry away, are returned to •

it

Arabian

shores are

and none of

blow over

it

again in the shape of rains.

Johuston's Physical Atlas.

J^ficj^njl;

''""^

170

The Red Sea vapours are

CHAPTER

—-

THE PHYSICAL GEOGRAPHY OF THE carried off

SEA.

and precipitated

VII.

-

Cause of depression

The depression

elsewhere.

summcr

^^ ^^^ gffggj;

in Its leveL

in

tlie

time, therefore,

it

level of its

appears,

is

head waters

owing

as well as to that of the of evaporation ^

to the

wind blow-

ing the waters back. §

The evaporation

408

Supposed

parts of the Indian Ocean'

in certain

is

from three-fonrths of an inch to an inch

it

for tlic

evapoia

Red Sea

in the

summer time

tion.

Suppose ' '

daily. ''

averatre

to average '' ° only

^

an inch a day.

half §

409

Averac-e velocity of

current runnini; into

it.

Now,

we

if

suppose the velocity of the current which

runs iuto that sea to averacre, ° from mouth to head twenty milcs a day, it would take the water fifty days to reach ^ ''

»/

the head of

If

it.

by evaporation

it

daily,

lose half it

the Isthmus of Suez,

an inch from

would, by the time

its

surface

it

reaches

twenty-five inches from

lose

its

surface. §

410

waters lower at Its

Babehnan deb.

Thus the waters of the Red Sea ought ^|^g

to be lower at

Isthmus of Sucz than they are at the Straits of Babel-^

^^''^^i^isb-

Independently of the waters forced out by the

they ought to be lower from two other causes,

wind,

namely, evaporation and temperature, for the temperature of that sea

than §

411

Illustra-

it is

is

necessarily lower at Suez, in latitude 30°,

at Babelmandeb, in latitude

To make Sea

is

it

1 3°.

Red

quite clear that the surface of the

not a sea

level,

but

is

an inclined plane, suppose

tion.

the channel of the

and

level floor,

Red Sea

to

have a perfectly smooth

with no water in

it,

and a wave ten

feet

high to enter the Straits of Babelmandeb, and to flow up the channel at the rate of twenty miles a day for days, losing daily,

by evaporation,

to perceive that, at the

end of the §33.

half an inch

;

fifty

it is

fiftieth day, this

easy

wave

.

CURRENTS OF THE would not be so high, by two

171

SEA.

feet (twenty-five inches), as chapteb

— VIX.

it

was the

day

first

The top

it

commenced

of that sea, therefore,

inclined plane,

made

so

to flow.

may

be regarded as an

But the salt water, which has lost so much of its freshness by evaporation, becomes Salter, and therefore heavier. The liffhter water at the Straits cannot balance the heavier water at the Isthmus, and the colder and Salter, and theremust

fore heavier water, rent, or it crystals,

must deposit

and thus

make

either run out as

make

Red Sea

brine

infer that there is

Red

is

know

going on.

that

Hence

from the Red Sea an mider or outer

from the Mediterranean through " the waters near Straits of Gibraltar, and that the surface

current,' as there

is

Suez are

than those near the mouth of the Red

salter

413

the salt from the

all

—and we

neither the one process nor the other

we

§

an under cur-

the bottom of the

must abstract

it

the

412

sm-plus salt in the shape of

its

gradvially

Sea a salt-bed, or ocean to

§

by evaporation.

pf^^,^'""^®

"'"^^ current

^°'"J''^

Red

S;;x

Sea.

And, to show

why

there should be an outer and under

current from each of these

two

seas,

let

us suppose the

case of a long opening o trough, o o into a vat of 1 '

oil,'

with a

partition to keep the oil from rrmning into the trough.

Now

suppose the trough to be

filled

up with wine on

one side of the partition to the level of the other.

The

water as

it

oil

is

and

by evaporation, and

heavier.

on the

enters either of these seas from the ocean,

and the wine the same water freshness

oil

introduced to represent the lighter

Now

what would take

after it has lost

therefore has

some of

become

its

salter

suppose the partition to be raised,

place

?

Why,

the

oil

would run

in as

§

414

"g^^^"'

"pperand under cur. '"^"'^

THE PHYSICAL GEOGRAPHY OF THE

172 ,'HAPTER

an upper current, overflowing the wine, and the wine

would run out as an under

1

The

415

§

rivers

current.

which discharge

in the Mediten-anean are

not Sufficient to supply the waste of evaporation, and

Beautiful

cnnipensa- is

which

.

by a pfoccss ,

„

,

Similar to .

,

preserves

ricd lu irom the ocean

brium of

were

it

solid

not

so,

1-1 this that

••!

Bvstem of tion

SEA.

^

•

^

^

the salt which -,

is

it

•

car-

is

,

returned to the ocean again;

the bed of that sea would be a mass of

The equilibrium

salt.

1

of the seas

is

preserved,

beyond a doubt, by a system of compensation as exquiby which the

sitely adjusted as are those

spheres" §

416

It

is

immense

music of the

maintained.

difficult to

is

"

form an adequate conception of the

quantities of solid matter, in solution, which the

current from the Atlantic carries into the Mediterranean.

In the abstract log

for

March

1855, Mr. William

8th,

Grenville Temple, master of the United States ship Levant,

Extract

homeward bound, has described "Weather fine; made 1|

ofc.s.ship

stood in to Almiria Bay, and anchored off the village of

Roguetas.

the indraught there:

At noon,

lee- way.

pt.

Found a great number

of vessels waiting for

a chance to get to the westward, and learned from them that at least a thousand sail are weather-bound between this

and

Some

Gibraltar.

of

them have been

so for six

only to

weeks, and have even got as far as Malaga,

be swept back by the current.

Indeed, no vessel has

been able to get out into the Atlantic

for three

months

past." §

417

stroncurrent

Now, suppose back

this

this fleet for so

current,

many

which

and beat

baffled

days, ran no faster than

two

in-

to the

knots the hour.

Mediterraneaa.

and

Assuming

its

depth to be 400 feet only, .

itii

widtli seven miles,

and that

it

.

,

.

•

i

carried in with

•

it

CURRENTS OF THE

the average proportion of solid matter

—

contained in sea water

173

SEA.

—say one

thirtieth chapter

—

VII. -

and admitting these postu-

;

hites into calculation as the basis of the computation, ittionasto

appears that

salts

enough to make no

less

than 88 cubic

miles of solid matter, of the density of water, were carried into the Mediterranean during these

were some escape

unless there

for all this

which has been nmning into that merely, but for ages,

ranean would, ere

it

sea,

Now,

days.

soHd matter,

not for 90 days

very clear that the Mediter-

crystals.

Let us see the results of actual observation apon the

Red Sea and

density of water in the •'

the MediteiTanean,

'

and upon the under currents that run out from these ^ SeaS.

Four or

cm-^

""'

have been a vat of very strong

this,

bed of cubic

brine, or a

is

90

sait ear-

JJfig

five years ago,

Mr. Morris, chief engineer of

§

418

^^™'^y

§

419

the Oriental Company's steam-ship Ajdaha, collected spe-

cimens of Red Sea water

all

by Dr. Giraud, who reported Latitude.

D

No. No. No. No. No. No. No.

the

way from Suez

to the

Babelmandeb, which were afterward examined

Straits of

1.

2. 3.

Sea at Suez Gulf of Suez Red Sea

the following results:* Longitude.

greea.

—

Spea Grav.

Degrees.

Saline Coat. 1000 p«rU,

27.49

33.44

1027 1026

40.0

24.29

36.

1024

39.2

1026 1024 1024 1023

40.5

4.

do.

20.55

38.18

5.

do.

20.43

6.

do.

14.34

40.03 42.43

7.

do.

12.39

44.45

41.0

mouth

of the

Red

Sea,

Bombay Geograph. Soc,

toI. is.,

May

Giraud.

39.2

and show that the surface waters at the head are heavier and Salter than the surface waters

* Transact, of the

by Dr.

39.8

tions just annoimced,

at the

Results reported

39.9

These observations agree with the theoretical deduc-

1849 to August 1850.

°'

water in '^edsea and Medlterraneaa

§

420

THE PHYSICAL GEOGRAPHY OF THE

174 criAPTKK

SEA.

In the same paper, the temperature of the

air

between

"and

Suez and Aden

often rises,

^ ^ Tempera-

bablv averasres

little less

tureofair

yg^r round.

Suez and

g5° ^g 85°, and the difference between the wet and dry

'-

JO

The

is said,

it

90°,

to

and than 75° day ^

bulb thermometers often amounts to 2 5° Average

or dcscrt wiuds, to from 30° to 40°

tiou.

ration at

Aden

;

—

the

"^

_

_

in the kamsin,

the average evapo-

about eight feet for the year."

is

gi-eater

the evaporation of

"

assuming," says Dr. Buist,

Sea to be no

niorht all o

surface of this sea varies in heat from

'

A ilea.

pro-

Now, the Red "

than that of Aden, a sheet of water

eight feet thick, equal in area to the whole expanse of Assump-

be carried off annually J in vapour I

t,hat sea, will '

tiou of Dr.

: >

or,

assum-

'

_

ing the

Buist.

average

Red Sea

most —and — whole this,

the

the fact

hundred

to be eight

of

assuredly,

it

feet in is

depth at an

more than double

would be dried

up,

were no

water to enter from the ocean, in one hundred years.

The waters of the Red Sea, throughout, contain some or, as salt is a half four per cent, of salt by weight or, in heavier than water, some 2.7 per cent, in bulk

—

round numbers, say three per

cent.

—

In the course of

three thousand years, on the assumptions just made, the

Red Sea ought

to

have been one mass of

solid salt,

if

there were no current running out." §

422 '*

Now we know sand years

old,

tinee^*''

thoiisan.i

years

old.

the

Red Sea

and that

it

is

423

l\'.[^'[l^'

cu: rents,

;

currents bring that as fast as the upper ° the ' salt in at the top, the under ciuTents carry it out at the

^hc rcasou

is,

^

bottom. §

more than three thounot filled with salt and

is

Mediterranean Currents.

—With

current from the Mediterranean, j,,^.

|.j^jj^^

^y^,

j^^Q^y that tlicrc

is

regard to an under

we may begin by remarka cm-rent always setting

1

CURRENTS OF THE li:

SEA.

]

and that

at the sm-face from the Atlantic,

this

is

a salt- chaptes

water current, which carries an immense amount of

We

into that sea.

salting

up

and

;

know, moreover, that that sea

75

is

—

salt

not

therefore, independently of the postulate,^

and of observations, we

the existence of an

niio^ht infer

Existence of an

under current, through which this .

into the broad ocean

With regard

salt finds its

way

out

to this outer

under current

.

again.'*'

inferred

and under

cuiTent,

we have

observations re-

observations telling of "

existence as long ago as 1712. gardingu

its

In the year 1712," says Dr. Hudson, in a paper com-

municated to the Philosophical Society ^

in 1724-, "

''

sieur

du

L'Aiffle, that fortunate *=

and srenerous

Moncommander

=>

chase near Ceuta Point to a Dutch ship bound to Holland, in the middle of the

Gut between

Tariffa

and Tangier, and there gave her one broadside, which

sunk

du L'Aigle

;

men

her, all her

and a few days

being saved by Monsieur the Dutch ship, with

after,

* Dr. Smith appears to have been the first to con/ec^wre this explanation, which he did in 1683 {vide Philosophical Transactions). This continual indraught into tlie Mediterranean appears to have been a vexed question among the navigators

and philosophers even of those times. Dr. Smith alludes to several hypotheses wliich had been invented to solve these phenomena, such as subterraneous vents, canties, exhalation by the sun's beams, &c., and then offers his conjecture, vhich, in his own words, is, " that there is an under current, by which as great a quantity of water

what

is

carried out as comes flowing

have said above about the

in.

To confirm which,

besides

and at the shore in the Downs, which necessarily supposes an under current, I shall present you with an instance of the like nature in the Baltic Sound, as I received it from an able seaman, who was at the making of the trial. He told me that, being there in one of the king's frigates, they went with their pinnace into the mid stream, and were carried violently by the current; that, soon after this, they sunk a bucket with a heavy cannon ball to a cei-tain depth of water, which gave a check to the boat's motion and, sinking it still lower and lower, the boat was driven ahead to the windward against the upper current the current aloft, as he added, tvjt being over four or five fathoms deep, and that the lower the bucket wa* let fall, they found the under current the stronger." I

diflference of tides in the ofiing

;

:

»

§ 401.

P'pei-by

^

of the privateer called the Phoenix, of Marseilles, giving

directly

424

Extract from a Dr. H4id-

,

came up with her

§

son.

— 1

THE PHYSICAL GEOGRAPHY OF THE

76

OHAPTEK lier cargo of '•

which

gier,

place

brandy and

is

oil, ai'ose

on the shore near Tan-

at least four leagues to the

where she sunk, and

SEA.

westward of the

directly against the strength of

the current, which has persuaded

many men

that there

is

a recun-ency in the deep water in the middle of the Gut that sets outward to the grand ocean, which this accident

very much demonstrates the water which

several of the

§425 Dr. woi-

observa tions on

density,

mentioned

;

otherwise,

have been driven towards Ceuta,

The water

in the

Gut must be very

deep,

commanders of our ships of war having

attempted to sound contrive,

the Straits returns that way,

coasts before

this ship must, of covu'se,

so upward.

and, possibly, a great part of

inins into

and along the two and

;

it

with th^ longest lines they could

but could never find any bottom."

In 1828, Dr. Wollaston, in a paper before the Philosophical Society, stated that he found the specific gravity

of six hundred of a spccimcn of sea water, from a depth ' ^

and scvcuty fathoms, " density

have a

fifty

miles within the Straits, to

exceeding that of distilled water by

more than four times the usual leaves,

excess,

and accordingly

upon evaporation, more than four times the usual

Hence

quantity of saline residuum.

it

is

clear that

under current outward of such denser water,

if

an

of equal

breadth and depth with the cuirent inward near the surface,

would cany out

much salt below as moved with less than

as

in above, although it

is

brought

one-fourth

part of the velocity, and would thus pi'event a perpetual increase of saltness in the Mediterranean Sea

beyond that

existing in the Atlantic." §

426

The doctor obtained Captain,

this

specimen of sea water from

now Admiral Smyth,

of the English navy,

who

CURRENTS OF THE had

collected

it

177

SEA.

Dr. Marcet died before

for Dr. Marcet.

chaptf.k VII.

receiving

and

it,

it

some time before It

had remained

came

it

hands

in the admiral's

into those of Wollaston.

may, therefore, have

lost

something by evaporation;

for it is difficult to conceive that all the river water,

§

427

and

three-fom-ths of the sea water which runs into the Mediterranean,

evaporated from

is

under current having

foiir

leaving a brine for the

it,

times as

much

salt as the

Very

at the surface of the sea usually contains.

M. Coupvent des Bois •

1

is

said to

recently,

observation of M.

have shown, by actual

coupvcnt

f

•

1

water

observation, the existence oi an outer

IT

'^'^^

Bois.

and umler current

from the Mediterranean.

However

may

that

be, these facts,

and the statements §428

of the Secretary of the Geographical Society of Bombay,^

seem

no room to doubt as to the existence of an

to leave

Factsieavt as to the

existence

under current both from the Red Sea and Mediterranean,

ofanumier current

and as to the cause of the surface current which flows into them.

accounted

think

I

it

a matter of demonstration.

It

is

by the salts of the sea. Writers whose opinions are entitled to great respect

differ tion.

for''

with

me

as to the conclusiveness of this demonstra-

Amonor these writers are Admiral Smyth, of the "^ ,

British navy,

each other. in

and Sir Charles

who

Lyell,

.

also differ

§

42

'J

Difference of opinion in regard

toit.

with

1820, Dr. Marcet, being then engaged

In

studying the chemical composition of sea water, the

admiral, with his usual alacrity for doing " a kind turn,"

undertook to

collect for the doctor si)ecimens of ^

Mediter-

ranean water from various depths, especially in and about the Straits of Gibraltar. fifty

Among

these

was the one taken

miles within the Straits from the depth of six hun-

dred and seventy fathoms (four thousand and '

«•

421.

»

§ 413. 12.

»

g

425.

specimens of water

twenty

collected rai

smyth.

THE PHYSICAL GEOGRAPHY OF THE

178 CHAPTER feet), y

SEA.

common

which, beinoj o four times salter than '

VII.

water,

as

left,

we have

^

just seen, no doubt in the

sea

mind

of

Dr. Wollastou as to the existence of this under cm-rent of brine. §

430

Depti: in

the Straits.

... But the

indefatigable admiral, in the course of his cele-

bratcd survey of the Mediterranean, discovered that, while

was upwards of nine hun-

inside of the Straits the depth

fathoms, yet

di-ed

in

the Straits themselves the depth

across the shoalest section

is

not more than one hundi'ed

and sixty* fathoms, sircharios Lyell's rte(luctions.

«

Such

bcincr ° the

we can now

casc,

prove," exclaims ^

_

Sir Charles Lyell, " that the vast

amount

of salt brought

agam by

into the Mediterranean does not pass out Straits

;

for it appears

the

by Captain Smyth's soundings,

which Dr. Wollaston had not

seen,

that between the

Capes of Trafalgar and Spartel, which are twenty-two miles

apart,

and where the

deepest part, which

two hunch'ed and

is

the

Straits are shallowest,

on the side of Cape Spartel,

twent}"" fathoms.

7

It

is

only

therefore evi-

is

dent, that if water sinks in certain parts of the Mediter-

ranean,

in

consequence of the

since

it

it

of

its

S})ecitic

two hundred and twenty

gravity, to greater depths than

fathoms,

increase

can never flow out again into the Atlantic,

must be stopped by the submarine barrier which

crosses the shallowest part of the Sti'aits of Gibraltar."}; §

According to this reasoning,

431

His ..aequine not conclusive

all

the cavities, the hollows

and the valleys at the bottom of the

sea,

the trade-wiud region, where evaporation

and great, ought

to be salting

* "Tlie Mediterranean."

J

Lyel. » Priiioiplea of lieulogy,

up or

filling

especially in

is

+ One hundred and 3"4-5. ninth edition.

p. '

g425.

so constant

up with sixty,

brine.

Smyth.

L'ludon. 1853.

— CTRKENTS OF THE Is

SEA.

probable that such a process

it

1

79"

actually going on

is

?

No.

chapter -

to this reasoning, the water at the bottom § 432 American lakes ouo^ht great to be salt, for the ^'"" ® ^ would be rivers and the rains, it is admitted, bring salts from the the effects

According

of the

land continually and em})ty them into the

It

sea.

is sreat

American

admitted that the great lakes would from this cause

also

lakes

if

this rpii-

be

The Niagara

they had no sea drainage.

salt, if

river

passes these river salts from the upper lakes into Ontario,

and the

Now far

St.

Lawrence conveys them thence

the basins or bottoms of

all

to the sea.

these upper lakes are

below the top of the rock over which the Niagara

pitches

its

And, were the position assumed by

flood.

namely, that

this writer correct,

if

the water in any of

these lakes should, in consequence of

its specific

gravdty,

once sink below the level of the shoals in the rivers and straits

which connect them,

never could flow out again,

it

and consequently must remain there principle physically correct,

for ever*

—were

would not the water

bottom of the lakes gradually have received

this

at the

salt sufiicient,

duiing the countless ages that they have been sending off"

to the sea, to

make

this everlastingly pent-up

it

water

briny, or at least quite different in its constituents from

that of the surface at

the

?

We may

water, whether salt or fresh, of specific gi-avity

ever

presume that the water

bottom of every extensive and quiet sheet of

;

but that

is it

we have abundant proof

at the

bottom by reason

does not remain there for If so, the Niagara River

would be fed by Lake Erie only from that layer of water which

is

above the level of the top of the rock at the

* See paragi-aph quoted (p. 17S)

from "

Lyell's Principles of Geology."

soninf:

rect

180

THE PHYSICAL GEOGRArHY OF THE Consequentl}^, wherever

CHAPTKE Falls.

— VII

'-

is

no greater than

it

current as rapid as

it

tlie

at

is

breadth of that river

we should have a the moment of passing the leap. To see that such is

at the

is

SEA.

Falls,

make the not the way of Nature, we have but to look at any common mill pond when the water is running over the dam. top of the rock to

The current

in the

perceptible, for "

know

it is

pond

tliat feeds

the overflow

water runs deep."

still

to another

wherever above the Niagara Falls the water

And the cm'rent

are sure to

with the rate it is

cause

assumes as

it

§

Assump-

it

tioii

The -^Q

on

which

it

is

;

for,

deep, there

sluggish in comparison

approaches the Falls

;

and

sluggish in deep places, rapid in shallow ones, beis

The common

fed from below.

our canals teach us this 433

we

not such a skimming current as the geologist

would make, which runs from one lake

we

scarcely

is

Moreover,

" w^astes " in

fact.

reasoning of this celebrated geologist appears to

that when water, in confounded upon the assumption • i-

Sir

Lyeiis

sequence of

specific

its

gi-avity,

bottom of a cuiTent where

it

is

once sinks below the shallowest, there

is

no

ojiiiiioii

was

force

of traction

in

fluids,

nor any other power, which

founded.

can di'aw this heavy water up again. case,

we

If such

were the

could not have deep water immediately inside

of the bars which obstruct the passage of the great rivers Rate at wliich

Jnto the sca.

Thus the bar at the mouth of the

sippi, witli

ouly fifteen feet of water on

Jlississippi

travel? out

Missis-

••ill

tlie

bar of the

to travel out to sea at rates varying

it,

estimated

is

trom one hundred

to sea.

to §

434

twenty yards a year. In the place where that bar was

thousand yards nearer to

whether

it

were

fifteen

New

when

Orleans than

it

it

was one

now

is,

years ago or a century ago, with

—

—

CURRENTS OF THE

SEA.

1

only fifteen or sixteen feet of water on four or five times tliat depth. sively formed seaward

where

had placed

specific gravity

— fomed.

and

lifted

top of the bar at

its

mouth.

He

up from

it

and canned

it,

own bottom

its

chapthb

what dug up the out to

it

from the sur-

feet

makes

Indeed, Sir Charles liimself

?

stream to tear up

we have now

old,

more than a few

sea over a barrier not face

old,

1

bars were succes-

As new

from the

sediment which formed the

it,

H

^

majestic

this

depths far below the

to

describes the Mississippi

as a river having nearly a uniform breadth to the dis-

He makes

tance of two thousand miles from the sea.* it

cut a bed for itself out of the

which

soil,

is

heavier

than Admiral Smyth's deep sea water, to the depth of

more than two hundi-ed feetf below the top of the bar which obstructs its entrance into the sea. Could not the same power which scoops out this solid matter for the Mississippi,

terranean, Straits

draw the brine up from the pool and pass

it

out across

the

in the

ban'ier

Medi-

in

the

?

Tlie traction of locomotives on rail-roads,

of that traction,

is

well

and the

force

Now, have not

understood.

currents in the deep sea power derived from some such force

Suppose

?

this

under current from the Mediter-

ranean to extend one hundred and sixty fathoms down, so as to chafe the barrier across the Straits.

bottom of than

fifty

i

the

a pressure of more •

this current, then, there is

atmospheres.

Upon

Have we not

here a source of

* " Prom near its mouth at the Balize, a steamboat may ascend for two thousand miles with scarcely any percejjtible Jilference in the width of the river." Lr/ell, p.

263.

+ " The

Mississippi

is

continually shifting

plain, cuttincr frequently to tlie

depth of two hundred and

its

course in the great alluvial

depth of one hundred, and even sometimes

fifty feet."

Li/ell, p.

273.

to the

§

435

Force of traction on laii-roads.

^tep-sel J^^ve^"^'^

v°"'\^^^

ilenved *^''°'" ^ like force.

THE PHYSICAL GEOGRAPHY OF THE

182 CHAPTER

SE-\.

power that would be capable of dra^vang up, by almost an insensibly slow motion, water from almost any depth

At any

rate, it

traction, or friction, or

whatever

force,

below the level of their beds in shallow

—were

not so

?

appears that the effect of cui'rents by

the brine not

does extend far

Were

places.

drawn out again

—

it

would

it

be easy to prove that this indraught into the Mediterranean

by

taken, even during the period assigned

lias

Sir

Charles to the formation of the Delta of the Mississippi

— one

of the newest formations

whole basin of the

the

—

enough to

salt

Mediterranean

Admiral Smyth brought up bottom with of deep sea water (six hundred

no §

436

M\mv»\

with

up

fill

oiystals.

his briny

sample

and seventy fathoms), but

salt crystals.

The gallant admiral }jot,h

—

appearing to withhold his assent

from Dr. Wollaston in his conclusions as to this

Smyth's euggestioii

under current, and from the geologist in his inferences as to the effect of the barrier in the Straits

—

suggests the

probability that, in sounding for the heavy specimen of sea water, he struck a brine spring.

But the specimen,

according to analysis, was of sea water, and

how

did a

brine spring of sea water get under the sea but through

the process of evaporation on the surface, or witli a portion of its fresh §

437

If Sir

^^

we admit

Lyell, that

Charles

by parting

water in some other

the principle

way ?

assumed by Sir Charles

water from the r> and basins of oreat pools i

tlie

i.ycirs

sea can never ascend to cross the ridges which form these

he admit-

pools

hfirmoni.s

and wc are forced

Ire cone.'

particlc of

and

basins, then the

Ipso facto,

harmonies of the sea are gone,

to conclude they never existed.

Every

Water that sinks below a submarine ridge

is,

by his reasoning, stricken from the channels

CURRENTS OF THE

for ever motionless chapter VII. „

become thenceforward

of circulation, to

183

SEA.

.

The consequence would be " cold obstruction the depths of the sea, and a system of circulation be-

matter. in

tween

different seas of the waters only that float

the shoalest reefs and barriers. existence of in

—

any such ''

I

any such imperfect

the theoretical proofs

— —

do not believe in the

mechanism, or

terrestrial

To

failures of desigTi. ®

above

my

mind, the proofs ^

'' _

Authm-s opinion.

^

the proofs derived exclusively

from reason and analogy

are as clear in favour of this

under current from the Mediten-anean as they were in favour of the existence of Leverrier's planet before

was

it

seen through the telescope at Berlin.

Now

suppose, as Sir Charles Lyell maintains, that none

of these vast quantities of salt

which

would not be

difficult to

438

this surface cm-rent

takes into the Mediterranean find their It

§

show, even

way

out again.

to the satisfaction

of that eminent geologist, that this indraught conveys

away from the Atlantic faster than all the /res/i- water Now, I'ivers empty ^'' fresh supplies of salt into the ocean. salt

^ ^

_

besides this dj'ain, vast quantities of salts are extracted

from sea water for madi'epores, coral

and marl beds

;

perfectly sound this

reefs,

and by such reasoning as and good, we

imder current, or

else

we

and becoming

less

and

this

-^

we

this,

must be

less briny.

examining features of ® the physical ^ its conditions,

shell banks,

which

is

are led to look for

...

—By

sea,'' '

losing

sheiis,

carefully § 439

and study^

warm

currents .

volumes of overheated water, probably exceeding in 1

thefom.ii-

its

that have their genesis in this ocean, and that carry from it

fiomseawaler for

are forced to the very un-

The Currents of the Indian Ocean. ing

is

extracted

establish the existence of

[ihilosophical conclusion that the sea salts,

sait

_

Plates VIII and IX.

wanncurrents in

Indian Ocean.

THE PHYSICAL GEOGRAPHY OF THE

184 CHAPTER

—

'•

Gvilf

times

Stream from

which

tliat

discharged by the

is

fountains (Plate VI.).

its

Ocean

Tlie Atlantic

440

§ Facts

many

quantity

open at the north, but tropical

is

bound the Indian Ocean

countries

SEA.

that

in

direction.

s'.iow tlieir

e.xisteuce.

The waters

of this ocean are hotter than those of the is much we might, without observa-

Caribbean Sea, and the evaporating force there'

That

greater.

from the fact of a higher temperature and a

tion, infer

Mozambique current.

§

gi-eater

amount of

shores.'

These two

seem, to

show that

Straits

it

One

of

them

called at the

Another of these currents makes

would

warm water have

currents of

lai-ge

weU-kuown Mozambique current, Good Hope the LaguUas current.

the

is

Gape

of

escape through

its

by other warm

the Straits of Malacca, and, beinsr joined '^

streams from the Java and China Seas, flows out into

through tiie

neighbouring

the

taken together, tend,

current e-^cipes

on

precipitation facts,

their ° crenesis in the Indian Ocean.

441

Another

greater

it is

_,

_

^

tlic Pacific,

like another

.

.

Gulf Stream, between the Philip-

of Malacca

Thence

pines and the shores of Asia.

it

attempts the

great circle route^for the Aleutian Islands, tempering mates, and losing itself in the sea on

its

cli-

route toward the

north-west coast of America. §

Between the physical features of

442

I'ointsof

this current

and the

Gulf Stream of the Atlantic there are several points of

resein-

hiancebetwcen tliis

rcsemblance.

current and the

and Cuba

iif

Sumatra and Malacca correspond

to Florida

Borneo to the Bahammas, with the Old Provi-

;

dence Channel to the south, and the Florida pass to the

Stiram.

west.

The

coasts of

China answer

States, the Philippines to the

to

Newfoundland.

here with

tliis

§ 210.

«

g

United

Bermudas, the Japan Islands

As with

the

China current, »

to those of the

Gulf Stream, so also

tliere

202.

is

'

a counter-current

§ 53.

CURRENTS OF THE of cold water between

and the

it

185

SEA.

The

shore.

the Asiatic coast correspond with those of

climates of chapter

America along

and those of Columbia, Washington, and

the Atlantic,

Vancouver, are duplicates of those of Western Europe

and the British Islands

the climate of California (State)

;

resembling that of Spain regions of deserts

its

Lower

California reminding one of Africa, with parallels, &c.

like the

Pacific,

North

Atlantic,

warm

with mists waters go, ° and streaked with lightning. The Aleutian

enveloped, where these '

the sandy plains and rainless

between the same

Moreover, the North is

;

§

443

Fogs and mists.

_

and

fogs,

Islands are almost as renowned for fogs and mists as are

the

of Newfoundland.

Grand Banks

A

sui'tace

current flows north through Behring's Strait

into the Arctic Sea

:

§

444

is Current through sur- Beiinngs

but in the Atlantic the current

from, not into the Arctic Sea

:

it

flows south on the

strait.

face,

north below

;

Behring's Strait being too sliallow to

admit of mighty under cm-rents, or to permit the introduction from the polar basin of any large icebergs into the Pacific.

Behring's Strait, in geographical position, answers to Davis's

Strait

in

the Atlantic

; '

and Alaska, wdth '

Aleutian chain of islands, to Greenland. there beinor ® to the east of Alaska, as there

its

445

Behiins's strait

But instead of to the east

is

§

with tho^f

ofDaviss _

of Greenland, an escape into the polar basin for these

warm

waters of the

turns them

Pacific, a shore-line intervenes,

down through a

sort of

cool

water upon the

marked.

Being

The

effect of this

They body of

littoral climate of California is

cool,

it

gives

and

North Sea along the

western coast of the continent toward Mexico.

appear here as a cold current.

freshness

and

currents

compared

very

and strength

strait.

1

THE PHYSICAL GEOGRAPHY OF THE

S6

summer

CHAPTER to the sea-breeze of that coast in

—

'-

" coolinor

is

most

These contrasts show

446

§

ijiffeience

sea-breeze"

SEA.

when

time,

the

crratefuL

principal points of resem-

tlie

blance and of difference between the currents and aque-

between currents

The

qus circulation in the two oceans.

ice-bearing ° cur-

of Xorth _

Atlantic

rcnts of thc

North Atlantic are not repeated

as to

volume

and North Pacific

North

the

in

Pacific,

for there

bergs like the frozen ocean and

Okotsk and Kamschatka

no nursery for

is

its

447

§

Current of

warm

water from the Indian Ocean.

is,

ice-

seas of

and not the frozen seas

alone,

North

of the Arctic, cradle the icebergs for the

There

The

arms.

Pacific.

at times at least, another current of

wami

way

south

water from the Indian Ocean.

midwav between

It finds its

Africa and Australia, and appears to

*^ ,

.

,

.

strewed with

lose itsclf in a sort of Sargasso Sea, thinly

Tlie whales also^give indications of

patches of w^eed.

Nor need we be

surprised at such a vast flow of

it.

warm

water as these three cun-ents indicate fi-om the Indian Ocean,

when we

recollect that this ocean^ is land-locked

on the north, and that the temperature of is

waters

There must, therefore, be immense volumes of water

448

§

its

frequently as high as 90° Fahr.

flowing into the Indian Ocean to supply the waste created

by

these

warm

cuiTcnts,

and

tlie fifteen

or twenty feet of

water that observations^ tell us are yearly carried this §

449

Ice bearliiu

cur-

'«"t'^

On ^|jg

off

from

ocean by evaporation. either side of this

intcr-tropical 1

between

Afi'ica

found wending

parts r

and its

warm

cun-ent that escapes from

Indian

of the

way from

Ocean,* midw^ay >

and

aqueous equilibrium in that part of the world. i'bie IX.

2

§ 439.

3

is

the Antarctic regions with

supplies of cold water to modify climates,

>

.J

an ice-bearing current'

Australia,

§ 33.

*

i

U7.

«

restore the

The

pi^te [X.

cur-

CURRENTS OF THE up

rent that flows

to the

SEA.

west of this

]

87

vreecly sea is the chapter

—

"vn.

Its bergs occasionally interfere

greatest ice-bearer. vessels

bound

by the new route

to Australia

The former sometimes

the other seldom.

40° south.

far north as the parallel of

;

'-

with

those of

drifts its ice as

The Gulf Stream

seldom permits them to get so near the equator as that in the

mg

North Atlantic, but 1

•

have known the ice-bear-

I

f

1

South Atlantic to convey of 37° south latitude.

TT

r^

•

Cape Horn mto the

current which passes east oi

Nearest approach

oncebfiRs

bergs as far as the parallel

its

This

is

the nearest approach of

icebergs to the equator.

These currents which run out from the inter-tropicai

—

basin of that immense sea

Indian Ocean

—

are

active

They convey along immense volumes of water containing vast quantities of salt, and we know that sea currents.

water enough to convey back equal quantities of

and

salt to

must flow of the

keep up into or

same sea

upon the

svipplies for the

return

450

^"''"^

Ocean currents.

salt,

outgoing currents,

the inter- tropical regions

to

therefore,

;

if

observations were silent

reason would

subject,

§

us

teach

currents here that keep in motion

to look for

immense volumes of

water.

The Currents of the

Pacific.

drawn^ between the China or

—The

contrast has been

Gulf Stream" of the North

Pacific,

and the Gulf Stream of the North

Atlantic.

The

course of the China Stream has never been satisfactorily -

§

451

cunenta of the

./»

-r»

"

1

traced out.

.

There

s

is

Mexico, a southwardly

Pacific.

chma. stream.

along the coast of California and

movement

of waters, as there

is

along the west coast of Africa toward the Cape de Verd Islands.

In the open space west of this southwardly >

S 442.

2

Plate IX,

set

along

§

452

THE PHYSICAL GEOGEAPHY OF THE

18S

famous Sargasso

CHAPTEK the African coast, there is the VII.

.

is

SEA. Sea,^

which

.

the general receptacle of the drift-wood and sea-weed So, in like manner, to the west

Pacific

of the Atlantic.

Sargasso

California of this other southwardly

from

the pool into

set, lies

which the drift-wood and sea-weed of the North

Pacific

are generally gathered, but in small quantities. §

The natives of the Aleutian

453

Islands,

where no

trees

grow, depend upon the drift-wood cast ashore there for the timber used in the construction of their boats,

all

and household

fisliing-tacle,

Among

gear.

this

timber,

the camphor-tree, and other woods of China and Japan, Evidence regarding

.^^q ^^^[^

the China

additional evidence

^q

\)q

Stream. _

In this fact

often recogniscd. ^

we have

touching ^ this China Stream, as to " The Japanese," says known. at best is _

_

which'' but little

Lieutenant Bent,* in a paper read before the American Geogi'aphical Society, January, 1856, "are well aware of its existence,

and have given

or Black Stream, which

deep blue colour of

its

is

it

the

name

of

'

Kuro-Siwo,'

undoubtedly derived from

tlie

when compared with that From this we may infer" that the

water,

of the adjacent ocean."

blue waters of this China Stream also contain more salt

than the neighbouring waters of the §

454

c..id cur-

The Cold Current of Okotsk. ter to the

rent of

Dkutsk.

is found"*

inff

coast.

Inshore

of,

but coun-

China current, along the eastern shores of Asia, *= '

a streak, or layer, or cmrent of cold water answer-

to that

strono-

—

sea.

between the Gidf Stream and the American

This current, like

enough

navio-ation

;

its

fellow in the Atlantic,

is

not

at all times sensibly to affect the course of

but, like that in the Atlantic,

it

is

the nur-

* Lieutenant Bent was in the Japan Expedition with Commodore Perry, and used the opportunities thus afforded to study tlie phenomena of this stream. >

Plate IX.

'

§

45L

»

§ 4.

§ 442.

1

CURRENTS OF THE most valuable

eery' of

The

fisheries.

are quite as extensive as those of

189

SEA.

Japan

of

fisheries

chapter

—

Newfoundland, and the

people of each countiy are indebted for their valuable

'-

of

j^pa^

§

455

supplies of excellent fish to the cold waters which the

currents of the sea bring

Humboldt's Current. but

little

down

Among

understood.

to their shores.

—The

cuirents of the Pacific are those about which most

is

Humboldt s

known is the Humboldt Current of Peini, great man whose name it bears was the first to

thought to be

which the discover.

It

has been traced on Plate IX. according to

the best information

This current

ject.

—

defective at best

is

felt

The Andes, with

delightful

—upon

tlie

sub-

the equator, miti-

far as

as

gating the rainless climate of Peru as it

it

goes,

and making

their snow-caps, on one

of the naiTOW Pacific slopes of this inter-tropical

side

republic,

and the current from the Antarctic regions on the

make

other,

world

;

for,

its

climate one of the most remarkable in the

though torrid as to

latitude, it is

temperature that cloth clothes are seldom

dming any time

such as to

felt as

oppressive

of the year, especially after nightfall

Between Humboldt's Current and the great equatorial flow there

is

an area which

may

be called the " desolate

was observed that this part of the ocean was why, visited by the whale, either sperm or right

region."* i-arely it

It

;

did

not appear

;

but observations asserted the

fact.

Formerly, this part of the ocean was seldom whitened by the sails of a ship, or enlivened

by

the presence of man.

Neither the industrial pursuits of the sea nor the high-

ways

of

commerce

called

him

into

it.

Now

and then a

roving cruiser or an enterprising whaleman passed that

way

cunent.

;

but to

all else it

'

§ 70.

was an unfrequented part of '

Plate IX.

tlie

§

456

?]g*„,,.,.,

^^s'°"-'

1

THE PHYSICAL GEOGRAPHY OF THE

90

and

CHAPTER ocean,

—

and

'-

so remained until the gold-fields of Australia

guano islands of Peru made

tlie

bound from Australia

All vessels Sea-buds fc/jow

SEA.

^.

it

a tlioroughfare.

South America now

to

pass throusfh ^ it, and in the journals of some of them it is n i-n described as a region almost void of the sio-^s of life in

.„,.

.

both sea and

air.

where there

is

In the South Pacific Ocean especiaEy,

such a wide expanse of water, sea-birds

often exhibit a companionship with a vessel, and

company with

follow and keep

Even

weeks together.

for

it

those kinds, as the albatross

and Cape pigeon, that delight Cape Horn and

summer

But not this

In

rp^^^

regMn

accompany

clears Australia sea-bu'ds that ioin the ship r as she said, follow

is

Even the

ap])ear.

her to this region, and then disof the stormy-petrel ceases to

chii-p

be heard here, and the sea baiTen of

457

A warm current discovered

f.omtiie

vessels into the per-

of the tropics. ''

will, it

§

stormy regions of

in the

the inhospitable climates of the Antarctic

regions, not unfrequently

petual

will

through storm and calm

"

moving

itself is

said to be singularly

creatures that have

life."

I have, I believe, discovered the existence of a

cmTcnt

warm mid-

regions of the Pacific, froui the inter-tropical * °

-way between the American coast and the shore-lines of

This region affords an immense sm*face for

Australia.

inter-tropical re-

pions of tiiePadtic.

No

evaporation.

m

,

rain,

,

except

the evaporation south-east

rivers

empty

the " Equatorial is

all

into

it

;

the annual faU of

Doldrums,

>)

•

is

Ti

small,

that both the north-east

trade-winds can take up and carry

1

and

and the off.

I

have marked on Plate IX. the direction of the supposed

warm water

current which conducts these overheated and

briny waters from the tropics in mid ocean to the extratropical regions

where precipitation

is

in excess.

Here,

being cooled, and agitated, and mixed up with waters that

are

less

salt,

these

over-heated

and

over-salted

— S

CURRENTS OF THE waters from

tlie

tropics

may

SEA.

1

9

1

be replenished and restored chapteh

to their rounds in the wonderfid system of oceanic circulatioiL

There are also about the equator in this ocean some curious cm-rents which

do not understand, and as to

I

§

45

Cunous currents,

which observations are not

sufficient

yet to aflbrd the

not under stood.

There are

proper explanation or description.

many

of

On

them, some of which, at times, run with great force.

a voyage from the Society to the Sandwich Islands, I

encountered one running at the rate of ninety-six miles

a day.

And what

else

should

we

expect in this ocean but a

the system of cm'rents and counter-currents apparently A •'

''

•••

most

uncei-tain

The

and com})licated ?

the Indian Ocean may, in the view

be considered as one sheet of water.

we

Pacific

Ocean and

§

459

compiicateu system of currents

are about to take,

This sheet of water

covers an area quite equal in extent to one half of that

embraced by the whole sm'face of the earth ing to Alexander Keith Johnston, it

in the

total

new

annual

who

and, accord-

;

has thus stated

edition of his splendid Physical Atlas, the

fall

of rain on the earth's sm-face

is

one hun-

dred and eighty-six thousand, two hundi'ed and forty

Not

cubic imperial miles.

less

than three-foui'ths of the

vapour which makes this rain comes from waters

;

ninety-three

thousand,

taken up from

two hundred and water which this expanse.

down

waste of

is

it

at another,

and that that much,

fifty-five cubic miles as the

is

at

again as vapour, this would give

daily lifted It

i. e.,

one hundi-ed and twenty cubic

miles of rain falls upon this sea, least, is

tliis

but supposing that only half of this quantity,

quantity of

up and poured back again into

taken up at one place and rained

and

in

tliis

place, therefore,

we have

^f^Jj^'"""''

THE PHYSICAL GEOGRAPHY OF THE

192

CHAPTER agencies for multitudes of paiiial

—

.

in their set

all,

and

SEA.

conflicting current^

and strength, apparently as uncertain

as

the winds. §

The

460

suppi«i:a case.

better to appreciate the operation of such agencies

producing o currents in the sea, now here, now there, first this way, and then that, let us, by way of illusjj^

X

tration,

imagine a

two hundred and

district of

fifty-five

square miles in extent to be set apart, in the midst of the Pacific Ocean, as the scene of operations for one day.

We

must now conceive a machine capable of pumping water to the depth

up, in the twenty-four hours, all the

The machine must not only

of one mile in this district.

pump up and but

it

bear

off"

must discharge

creating currents that effects that

immense quantity of water,

again into the sea on the same

it

some other

day, but at

this

Now

place.

here

equivalent in

is

would be produced by bailing

four hours,

two hundred and

is

a force for

its results

to the

up, in tAventy-

cubic

fifty-five

miles

of

water from one part of the Pacific Ocean, and emptying it

out again upon anotlier part.

The cuiTcnts that

would be created by such an operation would overwhelm navigation,

and desolate the sea

;

and, happily for the

Atiiio^i h&-

liuman

agency,

actually does perform every day, on the average, all this

race,

the

great

lifting up, transporting,

atmospherical

and

letting

machine which

down

upon

of water

the face of the grand ocean, does not confine itself to

an area of two hundred and to

fifty-five

square miles, but

an area three lumdred thousand times as gi-eat

nevertheless,

the same

quantity of water

is

;

yet,

kept in

motion, and the currents, in the aggregate, transport

much water

to restore the equilibrium as they

a.s

would

CURRENTS OF THE have to do were oiu-

SEA.

93

]

the disturbance to take place upon cnArTEh

all

hypothetical area of one mile deep over the space of

two hundred and

we come

Now, when

square miles.

fifty-five

to recollect that evaporation

is

that

lifting up,

the winds are transporting, and that the clouds are letting

down every day reminded that

and by

actually such a

it

done by

is

body of water, we are

little

and

little

at a place,

breadths at a time, not by parallelopipedons

hair's

one mile thick

—

that the evaporation

is

most rapid and

the rains most copious, not always at the same place,

but

now

here,

now

there.

We

thus see actually existing

a force perhaps quite sufficient to give

in nature

—

conciudvations.

which mariners

to just such a system of currents as that find in the Pacific

rise

currents which appear to rise in

mid

ocean, run at unequal rates, sometimes east, sometimes

west, but

which always

lose themselves

where they

rise,

namely, in mid ocean.

Under Currents. U.

S.

schooner

"

—Lieutenant

J.

C.

Taney," and Lieutenant

Walsh, in the S.

P.

Lee, in

§

4g1

cnder currents.

the U.

S.

brig " Dolphin," both, while they were carrying

on a sj^stem of observations in connection with the

AND Current Charts, had

their attention

Wind

directed to

the subject of submarine currents.

They made some subject.

A

block of

by means of a

interesting

experiments upon the

wood was loaded

to sinking, and,

fishing-line or a bit of twine, let

down

to

the depth of one hundi-ed or five himdred fathoms, at the will of

tlie

experimenter.

just sufficient to

was then

A

small barrel as a

keep the block from sinking

tied to the line,

and the whole

I'oat.

13

let

float,

farther,

go from the

§

462

Experi-

THE PHYSICAL GEOGRAPHY OF THE

194 c

iAPTFR

To use

their

" It

expressions,

o^v^l

SEA.

was

woiiderfu],

VII.

indeed, to see this barrega

§463 Surprising lesiilt.

sea,

and surface

move

against wind, and

off,

current, at the rate of over one

knot an

hour, as was generally the case, and on one occasion as

much

The men

as 1 1 knots.

exclamations of surprise, for

in the

it

boat could not repress

really appeared as if

some

monster of the deep had hold of the weight below, and

was walking amazed §

4G4

F.xperi-

ments

off

with

it."*

Both

officers

and men were

at the sight.

The experiments in deep-sea soundings have also thrown light upon the subject of under currents. There i=

much

in

deep-sea simndings.

rcasou to belicve that they exist in

or almost all parts

all,

of the deep sea, for never in any instance yet has the deep-sea line ceased to run out, even after the

plummet

had reached the bottom. §

4G5

Sounding-

If the line be held fast in the boat,

showing,

when two

or three miles of

it it

invariably parts, are out, that the

lines broicen.

uuder-cmTcnts are sweeping against the bight of

what seamen

call

a siuigging force,

that no

it

with

sounding

twine has yet proved strong enough to withstand. §

466

Lieutenant

J,

P.

Parker of the United States

Lieuten-

" Cougress,"

er'sexperiment.

the coast of South America. _

frigate

attempted, in 1852, a deep-sea sounding _

ofl

...

He was

_

engaged with the

experiment eight or nine hours, during which time a line nearly ten miles long was paid out.

Night coming

on,

he had to part the line (which he did simply by attempting to haul

it

in)

and return on board.

Examination

proved that the ocean there, instead of being over ten miles in depth,

was not over

three,

and that the

line

was

swept out by the force of one or more under cm-renta * Lieuloiutnl Walsli.

CURRENTS OF THE But

in

what

195

SEA.

direction tliese currents were running

is

not chapter VII.

known. ,

It

may,

without doing any violence to

tlierefore,

tlie §

rules of philosopliical investigation, be conjectured, that

equihbnum

the 1

or less extent,

If

may

we

r>

system of cm-rents and counter-

down

it

briumof

surface.

and the

tides,

may

such as those that lay

garding equili-

this

except the

preserved, to a gi-eater

is

•

1

by

and below the

currents at

fiea,

of all the seas 1

4G7

conjec-

partial currents of the

be created by the wind,

we

Rule laid down, that ocean currsnts

as a rule^ that all the cmTents of the

ows

their ori-

ocean owe their origin to the difference of specific gravity

ference of

between sea water at one place and sea water at another

gravity of

wherever there

for

owing

to

such a difference, whether

is

it

;

be

difference of temperature or to difference of

saltness, &c., it is

at'diffnient

^'*"'"

a difference that distm'bs equilibrium,

and currents are the consequence.

The heavier water

goes toward the lighter, and the lighter whence the heavier

comes

for

;

and standing

two

same

at the

differing in specific gravity,'

fluids

level,

can no more balance each

other than unequal weights in

opposite

It

scales.

is

immaterial, as before stated, whether this difference of specific

gravity be caused by temperatm-e, by the matter

held in solution, or

by any other thing

;

the effect

is

the

same, namely, a cm-rent.

That the

it

holds in solution the same

sea, in all pai-ts,

kind of solid matter

waters in this place, where ^ never rains, are not Salter than the strongest brine :

'

that

its

'

§

468

^^°°^^

thatwa ^eis of ti.e

;

sea aie

and that in another

place,

where the rain

they are not entirely without

salt,

may

is

incessant,

be taken as evi-

dence in proof of a system of currents or of circulation in the sea, by which

its

^

waters are shaken

§ 31.

«

§ So.

u^)

and kept

shaken tip and mixe34

pmofafforded by Arctic Toyajjers.

direction of Davis' Straits, have afforded

^1^

'

observations,^ ^proof positive ^

as

to

tlie fact

source for supplying the Polar Seas with

by 'J

their

us,

of this other

They

salt.

tell

us of an under current setting from the Atlantic toward

They

the Polar basin.

high up in

tend far tearing

their

down into the depths of the ocean, ripping and way with terrific force and awful violence

sfidsiiip-

man Griffin.

way

ice,

or against a surface current, on

into the Polar basin.

Passed Midshipman

535

which ex-

ba.ses of

tlieir

through the surface

§

describe huge icebergs, with tops

and of course the

tlie air,

S. P.

Griffin,

who commanded

the

after O expedition I o Rescue in the American searching gjj. John Franklin, informs me that, on one occasion the

\)Y\ct

two vessels were endeavouring, when in Baffin's Bay, to warp up to the northward against a strong surface current,

which of course was setting

Iceberg

while SO engaged, an iceberg, with

against

the watcr.

tlie

" drifting o

Came

current.

to the south; its

top

from the up" i

many

south,

and that feet

above

and passed

_

by them "like a

shot."

Although they were stemming

a surface current against both the berg and themselves,

such was the force and velocity of it

tlie

under current, that

carried the berg to the northward faster than the crew

could warp the vessel against a surface but counter current. §

536

Captain Duncan, master of the

Dundee, rative

:

says, at

—

* Arctic Regions Sliip

;

English

page 76 of his interesting

Voyage

to Davis' Straits,

Duudee, 1S26, 1827. »

S 47S.

whale-ship little

nar-

by Dorea Duncan, Master of the

—

^

THE SALTS OF THK " Dec.

ISfh

from

was

It

[1826].

immense icebergs working

and not one drop of water

us,

behold the chaptk?

to

aw-ful

way

their

227

SEA.

to the north-east

they were

to be seen;

working themselves right through the middle of the

And

again, at page 92, &c.

ice."

—

'-

Duma,.^ onlc'e'^'^'''

:

"Feb. 2Sd. Latitude 68° 87' north, longitude about 63° west. "

The dreadful apprehensions that

us yester-

assailed

coiitinued

day, by the near approach of the iceberg, were this day

most awfully

came it

About three P.M. the iceberg and in less than one minute

verified.

in contact with our floe,

broke the

We

ice.

shore; the floe

were frozen in quite

was shivered

to

close to the

pieces for several miles,

causing an explosion like an earthquake, or one hundred

heavy ordnance

pieces of iceberg,

fired at the

same moment.

with awful but majestic grandeur

(in

The

height and

dimensions resembling a vast raoimtain) came almost up to our stern,

and every one expected

would have run

it

over the ship "

The

iceberg, as before

observed,

came up very near

to the stern of our ship; the intermediate space

the berg ice,

the a

and the

was

vessel

filled

between

with heavy masses of

which, though they had been previously broken

immense

compact body by

its

mass of

ice,

The berg was

pressure.

at the rate of about four knots,

by

were again formed into

weight of the berg,

and by

was pushing the ship before

its force

it,

as

it

drifting

on the

appeared,

to inevitable destruction.

"Feb.

away

24ith.

The iceberg

still

in sight,

but

driving

fast to the north-east.

"Feb

25th.

The

iceberg; that so latelv

threatened

oiu*

continue.!

THE PHYSICAL GEOGRAPHY OF THE

228

had driven completely out of sight

CHAPTER destiniction

—

'-

§

to the

north-east from us."

Now,

537

Author's

SEA.

q[jjq

opinion.

then, whence, unless from the difference of spe-

gravity due sea water of different degrees of saltness o o »'

and temperature, can we derive a motive power with tremendous masses of

force sufficient to give such

a velocity §

TrniiiiM-atiire

What

038

such

the temperatm-e of this under cm-rent?

Be

?

is

that what

ice

it

may,

it is

probably above the freezing point

of

under cur- ()f

Suppose

sca watcr.

Break through

to be at 82°,

it

the ice in the northern seas, and the temperature of the Tempera-

Water

surface

always

is

28''

;

at least Lieutenant

tnve of surface water.

Haven

so found

it

and

in his long imprisonment,

be supposed that, as

was with him,

it

so

it

it

De may

generally

is.

Assuming, then, the water of the surface current which rims out with the is

ice to

be

all

at 28°,

we

observe that

it

not unreasonable to suppose that the water of the under

current,

inasmuch as

fore

from warmer

if it

be not so

acrain,

must

it

comes from the south, and there-

latitudes, is

cold, its

probably not so cold; and

temperature, before

be reduced to 28°, or

it

comes out

whatever be the aver-

age temperature of the outer but surface current. Temjieia-

Kane fouud

Arrtic

Occau* as high as 36°.

Dr.

the temperature of the open sea in the Arctic

Can water flow

in the depths

below from the mild climate of the temperate zones to the sevei'e climate of the frigid zones without falling below

36°?

To what,

in

the depths of the sea, can a

current of large volume impart §

639

Moreover,

if it

gested, that there

its

warm

heat?

be true, as some philosophers have sugis

in the

depths of the ocean a floor or

plane from the equator to the poles along which the water

THE SALTS OF THE is

of

tlie

may be

same temperature

asked, Should

which

side of

the way, then the question chaptes

all

floor,

—

IX.

we not have

ocean a sort of isothermal

2 29

SEA.

in the depths of the

as

were, on the upper

it

'-

floor in the

the changes of temperature are due to

all

agents acting from above, and on the lower side of which, the changes,

if

any, are due to agents acting from below?

This under Polar current water, then, as top,

and

is

to the

it rises

brought to the surface by the agitation of the

§

540

c'-'"sp "f

watersky of tlie

sea in the Arctic Regions, gives out

surplus heat and

its

Polar

warms

the atmosphere tliere

warm under

current water

till

is

the temperature of this

lowered to the requisite

Hence the water-

degree for going out on the surface.

sky of those

And

regions.

regions.

the heat that

from

loses in falling

it

temperatm'e, be that what

it

may,

till it

its

normal

reaches the tem-

§

541

cause of modifica-

perature of 28°,

is

so

much

caloric set free in the Polar

Regions, to temper the air and mitigate the climate there,

Now,

is

tionof Polar climate.

not this one of those modihcations of climate

which may be

fairly traced

back to the

ness of the sea in giving energy to

Moreover,

if

its

effect of the salt-

circulation?

there be a deep sea in the Polar basin,

which serves as a receptacle

for the

waters brought into

§

542

Kasyto imaRine

it

by

this

under current, which, because

comes from

it

... imagme why

there

why

Lieu-

toward the equatorial regions, comes from a milder climate,

and

IS

therefore warmer,

might be an open sea

we can

easily

in the Polar

Regions

;

De Haven,

f

and why both he and Captain Penny, of one of the

)r it

;

was directed

there

might be an open sea in

tenant

in his instructionsj'

«hy

Poiar

to look

English searching vessels, and afterward Dr. Kane, found it tliere.

And

in accounting for this polynia,

"

§482.

we

see that

its §

543

THE PHYSICAL GEOGRAPHY OF THE

230 CHAPTER existence

—

is

not only consistent with

SEA.

hypothesis with

tlie

IX.

which we circulation,

Jits'ofsea

at least,

ty^uici'-^

salts

tulation of its

waters

if

but that

it

may

be ascribed,

m

a great degree

not wholly, to the effect produced by the

of the sea

upon the mobility and

circulation of its

,

WaXCrS.

Here, then,

544

§

touching a perfect sj'stem of oceanic

set out,

p.ioduced

an

is

which the sea performs in the

office

coneiud-

ecouomy of the universe by

marks.

whicli

And

viitue of

could not perform were

it

its

saltness,

its

waters altogether

and

fresh.^

have a clew placed in their hands

tlius philosopliers

Avhich will probably guide

them

to one of the

many

bid-

den reasons that are embraced in the time answer to the question, " § Sea

siieiis

Lime em-

Why

Sea Shells.

545

common

pic.ye.i in

rivers,

nnation.

of

it,

is

the sea salt?"

—We

find in sea

Lime

salt.

and emptied coral islauds

beds, shell -banks,

is

by the

rains

''

and the

in vast quantities into the ocean.

and

and

coi-al

Out

reefs of great extent, marl-

infusorial deposits of

nitude, have been constructed deep.

water other matter besides

dissolved

enormous mag-

by the inhabitants of the

These creatures are endowed with the power of

secreting, apparently for their

own

purposes only, solid

But

matter, which the waters of the sea hold in solution. this

power was given

to

them

the part assigned them in the Office of

.7

otthe df-ep.

546

fulfil

of the universe.

allotted the important

of assistiucr crivinar circulation to the ocean, of & in o 6 helping to regulate the climates of the earth, and of preofiicc .

serving the purity of the §

they also might

economy

For to them, probably, has been

the iniiabitants

tliat

The better

to

fluence cuirents

sea.

comprehend how such creatures may and

be perfectly at rest

in-

climates, let us suppose the ocean to ;

that througliout,

it

is

in a state of

;

THE SALTS OF THE complete equilibrium

231

SEA.

that, ^vith the exception of those chapteb

;

tenants of the deep which have the power of extracting Supposl-

from in

the solid matter held in solution, there

it

is

no agent

nature capable of disturbing that equilibrium

that

all

these

have suspended their

fish, &c.,

tton.

and

;

secretions, in

order that this state of a perfect aqueous equilibrium and repose throughout the sea might be attained.

In

this state of tilings

perfect equilibrium ^ *

suppose,

—

commences

a

—

the waters of

mollusc or coralline,

sincjle

°

we

will

§

547

Effect of

the opera-

secretions,

liis

sea being in

tlie

and abstracts from the

tionsofa single

sea water^ solid matter for his

In that

cell.

this

act,

coiaiiine.

animal has destroyed the equilibrium of the whole ocean for the

which

matter has been abstracted

this solid

Having

of that portion of water from

specific gravity

lost

a portion of

specifically lighter

than

its

it

altered.

is

become

solid contents, it has

was before

;

it

must, therefore,

give place to the pressure which the heavier water exerts to

push

it

aside

and

to

se([uently travel about

occupy

other parts of the ocean until ter is returned to

and

it,

its place,

and

must con-

it

and mingle with the waters of the its

proportion of solid mat-

until it attains the exact degi'ee

of specific gTavity due sea water generally.

How much plants

solid

matter does the whole host of marine

and animals abstract from sea water daily

a thousand pounds, or a thousand millions of tons .

one can say. r>ii

oi the

power

of the ocean.

?

No ,

.

•

11

^

And

this

power

is

loi-oniution.

•in

derived from the salts

marine animals, that of themselves scarcely

and other posse.ss

the

Yet they have power to put the ^

§493.

§

548

it soiid matter ab.

But, whatever be its weight, it is so much n T gravity applied to the dynamical forces

oi

of the sea, through the agency of sea shells

power of

Is

?

stracteci

fi'om sea

tymariie animals.

THE PHYSICAL GEOGRAPHY OF THE

232 CHAPTER

whole sea in motion, from the equator

SEA.

to the poles,

and

from top to bottom. §

Those powerful and strange equatorial currents^ which

549

Probable cause of

naviorators tell us they encounter in the Pacific Ocean, to °

currents in

what

"^

are

Coming from

they due?

unknown,

sources

tat- Pacitic.

they are

lost in the

no doubt,

some

to

They

midst of the ocean.

are due,

extent, to the effects of precipitation

and evaporation, and the change of heat produced thereby.

But we have yet

to inquire

how

far

may

they

be due to

the derangement of equilibrium arising from the change of specific gravity caused

by the

secretions of the myriads

of marine animals that are continually at

work

in those

These abstract from sea water solid

parts of the ocean.

matter enough to build continents of

And

also

we have

to inquire as to the extent to which equilibrium in the

sea

distm-bed

is

by the

salts

which evaporation leaves

behind.

Thus,

550

§

when we view, wc

consider the salts of the sea in one

winds and the marine animals

Principles

point of

of antago-

^

nistic

operating upon the waters, and, in cei-tain parts of the

See the

ocean, deriving from the solid contents of the

same those

very principles of antagonistic forces which hold the earth in its orbit, §

551

Dynamical

and preserve the harmonies of the imiverse.

In another point of view, we see the sea breeze and the sca

sliell,

in

performing their appointed

offices,

acting

forces.

so as to give rise to a reciprocating

and thus they impart

to tlie ocean

motion in the waters; dynamical forces also

for its circulation. §

The

552 sea

The fresli

sea breeze plays

upon the

surface

watcr into vapour, and leaves the

;

it

converts only

solid

matter be-

bieeze.

hind.

The

surface water thus

^

becomes

§458,

specifically heavier,

^

THE SALTS OF THE and

On

sinks.

the other hand, the

233

SEA. little

marine architect

chapter

—

below, as he works upon his coral edifice at the bottom,

abstracts from the water there a portion of its solid con- anacoun tents

therefore becomes specifically lighter,

it

;

and up

it

goes, ascending to the top Avith increased velocity, to take

the place of the descending column, which, of the winds, has been sent

and materials

for the

busy

down

by the action

loaded with fresh food

mason

little

in the depths

below. Seeing, then, that the inhabitants of the sea, with their

powers of secretion, are competent to exercise at least

§

552

Position

assigned

some degree of influence

in disturbing equilibrium,

are

to iniiai.it-

ants of

not these creatures entitled to be recjarded as accents

which have their

ofiices

to

perform in the system of

oceanic circulation, and do not they belong to

o-eography? It is immaterial how & gresit or o f J that influence may be supposed to be for, be

'='

;

we may

small,

but

it

and according

" voice

may

in the

to the

—

if

its

physical

how

small

^'"'^i'^'*'^'

to

ocean

^

it

great or

thi'msii

chance influence,

exercised at

commandment

the winds and the sea obey."

through sea It

rest assured it is not a

an influence exercised

is

design,

tli8

sea.

of

all

—by

Him whose

Thus God speaks

shells to the ocean.

therefore be supposed that the arrangements

economy of nature are such

as to require that the

§

553

^faii'ie

animals

various kinds of marine

animals, whose

secretions

are

distributed

according

calculated to alter the specific gravity of sea water, to

destroy

its

to order.

equilibrium, to beget currents in the ocean,

and to control

its

circulation, should be distributed ac-

cording to order.

Upon I'aiits

this supposition

—

the like of which nature war-

throughout her whole domain

—we

may

conceive

§

554

THE PHYSICAL GEOGRAPHY OF THE

234 cHAi'TEK

—

'-

how may

SEA.

we have been spealdng

the marine animals of which

impress other features upon the physical relations of

by

assisting also to regulate climates

and

to adjust

animals

the sea,

press'(ythei

the temperature of certain latitudes.

nrJpi^vsi"

su])pose the waters in a certain part of the torrid zone to

rionToitiie

^® ^0°>

"''^

by reason of the

^^*''

For

fresh water

instance, let us

which has been

taken from them in a state of vapour, and consequently

by reason of the propurtionate increase of waters are heavier than waters that

nut so

be

these

salts,

but

cooler,

This being the case, the tendency would be

salt.^

warm, but

for this

may

salt

and heavy water, to flow

off as

an under current towards the Polar or some other regions of lighter water. §

555

Now,

not

featurcs

sca shells

; '

and marine

upon the

;

and

as their temperature falls cm-rents,

its

and

torj)id,

its

nor give diveitsity

neither could evaporation give dynamical

force to its circulation,

impulse to

coral

and give variety to

specific gravity of its waters,

to its climates

would be no

insects could not operate ^

salt.

§ 5')(3

there

salt,

to beautify its landscape

'sl^'^'^^s

M°*^d*'f sea were

the sea were not

if

waters, ceasing to contract

its

below

39°,

and thus

would give but

its

little

would be

circulation

bosom lack animation.

its

This under current

may

be freighted with heat to

v'nder

temper some hyperborean region or to soften some extra-

freichtcd

tropical

with heat.

climatc, for „

effects of

been,

if

though quantity

we know

you its

please,

that such

.

.

marine currents.

.

At startmg,

so loaded

is .

it

among .

the

,

,

might have

with solid matter,

that,

temperature were 90°, yet, by reason of the

of

such matter held in solution,

its

specific

gravity might have been greater even than that of extratrojucal sea

water generally at »

§35.

28°.

THE SALTS OF THE Notwithstanding

this, it

may

"16.1

SEA.

be brought into contact, chapteh

by the way, with those kinds and quantities of marine that shall abstract solid matter enough to reorganisms ~ duce

than

its specific

common

gravity, and, instead of leaving

sea water at 28°,

sea water at 39° sea water,

when

it

_

make

it less

than

greater

common warm

consequently, in such a case, this

;

it

comes to the cold

would be

latitudes,

brought to the surface through the instrumentality of sh ell-fish,

and

various other tribes that dwell far

down

warm

water,

wlien it reacius colli !uti-

tudes,

biou-utro ,,y s!,t..u-

in

creatures,

though they are regarded as being so low in

the

of creation,

may

nevertheless be regarded as

much importance in the ten-estrial economy we now comprehend how they are capable of spread-

agents of for

This

Thus we perceive that these

the depths of the ocean.

scale

^—

;

ing over certain parts of the ocean those benign mantles of

warmth

less, all

wliich temper the

and modify, more or

win(.ls,

the marine climates of the earth.

The makers of

nice

astronomical

instruments,

wlien

toof their machinery they ^ ^ have put the different parts 1 I

getlier, and set °

to work, find, as in the chronometer,

it

§

558

Reautifni

and simple contnvaiice to ve-

for instance, that

it is

subject in

its

performance to man}'

siiiate

clironoine-

and imperfections

irregularities

things there tion,

among

is

to

overcome

;

that

in one

state

of

expansion, and in another state contrac-

and wheels,

cogs, springs,

diminution of

;

rate.

v^dth

an increase or

This defect the makers have sought

and, with a beautiful display of ingenuity,

they have attached to the works of the instrument a contrivance which has had the effect of correcting these irregularities,

by counteracting the tendency

strument to change

its

of the in-

performance with the changing

influences of temperature.

teis.

;

THE PHYSICAL GEOGRAPHY OF THE

236

This contrivance noraeter that

559

§

Compensrtiion.

§

perform

will

under

^.j^^g

it

may

compensation

and a

;

with certainty, and preserve

office

the vicissitudes of heat and cold to which

and regularity are maintained by a

uuiversc, ordcr

^]^g

'

A celestial

.

.

of the uni-

system of compcnsations. ^

verse.

around force

sun, flies

its

;

the planet

and held

Also in the

revolves

.

under the influence of centrifugal

ofl*

brought back to

is

in the orbit for

which

were adjusted.

its distance,

So, too, with the salts

561

of the

it

but immediately the forces of compensation begin

;

to act

machinery

body, as

*^

^

§

its

be exposed.

in the

machinery

cliro-

well regulated and properly compensated

its

all

called a

In the clock-work of the ocean and the machinery of

5G0

Analogy

is

is

SEA.

of the ocean machinery j

; >

Its

elliptical path,

its

motions, and

compensation

and the

is perfect.

shells of the sea in the

from them are derived xprinciples x

compensation the most perfect

t,f

its

mass,

its

through their agency

;

oc6iin.

tlie

undue

effects of

heat and cold, of storm and rain, in

distm-bing the equilibrium, and producing thereby currents

in the

sea,

are compensated, regulated,

and con-

trolled. §

The dews, the

562

Result

if

there were

dissolving: *=

certain

rains,

and the

rivers,

are continually

minerals of the earth, and carrying .

no com-

them

off"

This

to the sea.

is

an accumulativ^e process

pensation.

and

if it

w^ere not compensated,

become, as the Dead Sea

is,

the sea would finally

saturated with

therefore unsuitable for the habitation of

salt,

many

and

fish of

the sea. §

563

compen(sat

The sea sheUs and marine insects afford the required They are the conservators of the ocean. comveusation. "^

-^

ion

found

in

j\s

the salts

;u-e

emptied into the

sea,

these

creatures

sea shells

and the works of marine in soct*.

sccrcte

them

again, an

;

for the

"

going on

still

is

for ages

hard water" of our fountains, the

ua.

marl-banks of the valleys, the salt-beds of the Albion's chalky

monuments §

:

continually before

507

There

is

cliffs,

and the

plains,

coral islands of the sea, are

in attestation.

no proof, nor

is

there any reason fur the belief,

THE SALTS OF THE tliat

the sea

is

.

and

.

.

equal,

washing down

—

.IX.

and extraction are

reciSea grows

and

that the effect of rains

Ill

.

compensated by the processes

is

infer chapter

.

and secretion in taking

ration

Hence we

orowinor salter or fresher.

that the operations of addition procal

23.0

SE.V

rivers in c

oi

neither suiter nor

evapo-

ftesiier.

out.

If the sea derived its salts originally

the geological records of the past O ° ^

from the

rivers, §

would show that

river

568

inference.

Objection.

beds were scored out in the crust of our planet before the

'

'•'«

Darwin

sea had deposited

remains upon

any of If,

it.

theoiy,

we must

the sea

was without

its

fossi!

shells

and

we admit

therefore,

the Darwin pei'iod

when

and consecpiently without

shells

admit that there was a

also

salt,

infusorial

or animals either of the silicious or calcareous kind.

ever there were such a time,

it

were collecting and pouring

make

the brine of the ocean.

in the salts

which now

But while the

palseonto-

on one hand, afford no evidence

logical records of the earth,

any such

fresh -water period, the Mosaic account

from being negative with According ° to

it,

we

at least, as the fifth

If

must have been when the

rivers

of

tueorv

its

is

far

testimony on the other.

infer that the sea

was

salt as early.

Reductions from

day

for it

;

was on that day of

crea-

-^"saic

count

tion that the waters were

commanded

to

abundantly the moving creature that hath

bring forth It

is

iu

now teems with how abundantly the obedient waters do bring forth, and how wonderful for variety as well as multitude their progeny is. Ail who pause to look are astonished to see how the prolific ocean teems

obedience to that

organisms

;

and

command

"

life."

it is

and swarms with

that the sea

marvellous

life.

The moving

creatures in the sen

constitute in their myriads of multitudes one of the "

ders of the deep."

won-

ac

THE PHYSICAL GEOGRAPHY OF THE

240 CHAPTER

It

is

the custom of Captain Foster, of the American

IX,

-^ ^ ,.

Garrick,

ship ''

,

Captain Fosters obsevva-

who

is

one of

my

most patient of ob-

amuse himself by making o drawings o

servers,

to

abstract

log; o

'

SEA.

in hia

•/

of the curious animalculse which, with the '

microscope, he finds in the surface water alongside

tions.

though he has been following the sea never

to express his

fails

for

many

and

;

years, he

wonder and amazement

at the

immense numbers of living creatures that the microscope "Wonders j-eveals to

him

Hitherto his examinations

in sea water.

of the

related only to the surface waters, but in the log

deep."

before me he went

amazed than ever

to see

there bring forth. "

Animal-

Jan.

28th,

water,

sea

I

the depths, and he

into

1855.

how abundantly

— In

have," says he,

from the stern

examining animalculse " heretofore

pump

was

literally alive

beautiful varieties." purple, red,

There

570 as

§

571

The two

is

I

to find that the

with animated matter, embracing

Of some he

says, "

Numerous

heads,

and variegated," wonderful meaning in that word ABUNDANTLY,

stands recorded in that Book, and as

it

this

in

used surface

seven feet below the surface,

examined the water, and was surprised

§

was more

the waters even

This afternoon, after pumping for some time

water.

fluid

now

it

is

even at

day repeated by the great waters.

So t^],at

two records agree; and the evidence is clear the sea was salt when it received this command. far the

rctords 9g'*'c.

Do

they afford any testimony as to

ously

On

?

its

condition previ-

Let us examine. the third day of creation the waters were gathered

together unto

one

place,

and the dry land appeared.

Bt'fore that period, therefore, there were no rivers, and

W THE SALTS OF THE

241

SEA.

consequently no washings of brine, by mists, nor dew, nor chapter rains,

from the valleys among the This

the earth.

IX.

account which Nature has written, in her

on the mountain and in the

characters,

and

column

The

tions from

own

peculiar

and

on the rock

plain,

so,

peak

the solid parts

The

in the air,

geological evidence that

it

with perhaps the exception of a solitary mountain

and

liere

there, is conclusive

examine the

fossil

;

and when we come

remains that are buried in the

mountains and scattered over the

much

when

which now stand high

were covered by water.

was

on the geological

inscriptions

that there was a period

tell

of the earth's crust,

we have as when it covered, naturalist, when he

plains,

reason to say that the sea was salt

or nearly covered, the earth, as the

skuU or bone whitening on the wayside, has

sees a

say that

it

was once covered with

Therefore sea

and the

in the sea, as to the early condition of our planet,

indicates the same.

to

;

the account of Revelation

is

—

The water covered

hills.

was

we have " in

salt

to

flesh.

reason for the conjecture, that the

the

beoinninor," ° °

when

" the

waters

imder heaven were gathered together unto one place,"

and the dry land

we may

in the

§

572

conjecture that the se^

was

salt fi-nm

^

first

appeared.

For, go back as far as

dim records which young Nature has

the begin

left

upon the geological column of her early proand there we find the fossil shell and the remains

inscribed cesses,

of marine organisms to inform us that, tions of our

mountains were

laid

when

the founda-

with granite, and imme-

diately succeeding that remote period

when

the primary

formations were completed, the sea was, as salt

:

for, .

had

it ,

not been

salt,

it

is

whence could those

now, creep-

Reasons for thih.

.

uig things which fashioned the sea shells that cover the 16

— THE PHYSICAL GEOGRAPHY OF THE

242 CHAPTER tops

—

SEA.

or those madrepores that stiew the

of the Andes,

IX. '-

brmy

earth with sohd matter that has been secreted from deposits which

waters, or those infusorial geologist with their

astound the

magnitude and extent, or those

fossil

remains of the sea which have astonished, puzzled, and bewildered

been

salt

man

when

in

its

ages

all

;

whence, had not the sea

metes and bounds were

set,

could these

and

creatures have obtained solid matter for their edifices Effects of

.structm-es

?

IMuch of that part of the

up

in cultivation,

which

eartli's crust

nutriiie salts

on

man

stirs

has been

tion.

made

fruitful

and which yields him bread,

by these

" salts,"

which

Much

have secreted from the ocean.

shells,

of this portion of

our planet has been filtered through the sea insects

man-

all

ner of marine insects, aqueous organisms, and sea

and

;

its

and creeping things are doing now precisely what

they were set about when the dry land appeared, namely, preserving the purity of the ocean, and regulating it

As

in the due performance of its great offices.

fast as

the rains dissolve the salts of the earth, and send

down through

everlasting agents pearls, shells, corals,

and precious things

the land, by imparting

beauty and variety to

SeK-ari-

^]jj[g

justing piincipie

of nature.

sea,

new its

adaptations to

while

its

soil,

fresh

'

is

to

be found

beautiful and exquisite ^

...

systcm of Compensation, by which the operations of the -^

*'

.

most perfect 574

so,

landscapes.

this self-adiJ Ustinov o principle, r r

grand machinery of the

§

and

;

into

they are also embellishing

In every department of nature there

573

them

of the Creator elaborate

they are preserving the

§

them

the rivers to the sea, these faithful and

luiiverse

are maintained in the

order.

Whence came

the salts of the sea originally,

is

a ques-

THE SALTS OF THE

243

SEA.

tion which, perhaps, never will be settled satisfactorily to chapter

every philosophic mind

but

;

sufficient for the Chris-

it is

tian philosopher to recollect that the salts of the sea, like

waters and the granite of the

its

when reduced

substances which,

most

found, for the

mere gaseous or

Thus we say

matter of some kind or other. is

made

volatile in combination with

there

merely a

is

trace,

Now, was

tile.

the

and

of substances

oxvgen

volatile

felspar

tlien the three

Sea water

tile

is

fresh

were they made into

chaotic matter

tlie

?

find

and

them

in the

ocean, or

is

by some sub-

not material to our present purpose.

geologists suppose that in the chalk period,

when

sea,

ii

its

chambered •

1

1

shells, lived -aininK

-111 by these

the carbonaceous material required

creatm-es for their habitations

dant in

supposition re-

the ammonites, with their huge tlie

575

whether the sea was

.

i.1

§

primitive rocks, were brought together

the beginning," and became salt

.

;

and vola-

of formation, and united in combination as

sequent process,

Some

rock for the

gi-anitic

or

;

composed of oxygen and hydrogen

of the

in the process

" in

originally

But whether the constituents of sea water,

matters.

we now

granite

another, and the quartz

like the granite, also consist of gases

like those

which

brought together by some

upon

rock as they were formed of

its salts,

yet less

not gaseous or vola-

of the in

mighty power, and welded into the everlasting hills to stand

;

more or

Iron, of

g-as.

state, is

formed in one heap, the mica in a third,

sea.

the only ingredient which, in

is

uncombined and simple

its

fionotth*

that granite

generally compovsed of felspar, mica, and quartz

these three minerals are

m

are composed of

to their simple state, ai-e

to be

part,

hills,

waters than

it

must have been more abun-

now

is

;

but,

though the cou-

tlieclialk

peiiod.

THE PHYSICAL GEOGRAPHY OF THE

244'

water

CHAPTER stituents of sea

—

'-

forth,"

" its

The cuttle- feet in it

circumference,

is

twelve

shell

its

,

but then

:

the tiny nautilus, remains to

ami

with

no longer found alive in the sea

died out with the chalk period

The nauti- nion,

waters

widely different from what

It is true, the strange cuttle-fish,

§ ,j76

oorai in-

varied as to proportions,

they probably were never, at least since

commenced to bring they now are.

lus

may Lave

SEA.

us that even in

tell „

.

;

compa-

its

,

,

that Temotc period the proportion of salt in sea water

was not unsuited

to its health

have lived through

all

;

for

and the

it

coral insect

the changes that our planet has

undergone since the sea was inhabited, and they til at

its

in the

tell

us

least, as their

now

build

their

their habitations of the

same

materials, collected

records

make

waters were salt as far back, at extend, for they

same way, that they did then

edifices

and

and had the sea

;

been fresh in the interim, they too would have perished,

and their family would have become

extinct, like that of

the great ammonite, which perhaps ceased to find the climates of the sea, not the proportion of

its salts,

suited

to its well-being. §

tion of solid

Did any

577

computamat-

®

i\^Q rains, ever

ter held in

sniution as

one,

^vere orimnallv •'

who

maintains that the

washed down

into

it

salts of the sea

by the

rivers

and

''

...

take the trouble to compute the quantity

'

_

of solid matter that the sea holds in solution as salts

?

f.lltS.

Taking the average depth of the ocean at two its

average saltness at 3^ per

is salt

enough

in the sea to

cent., it

miles,

and

appears that there

cover to the thickness of one

mile an area of seven millions of square miles.

Admit a

transfer of such a quantity of matter from an average of

half a mile above to one below the sea level, and astro-

_

THE SALTS OF THE

245

SEA.

nomers will show, by calculation, that

it

would

alter the chapter

— I

length of the day.

These seven millions of cubic miles of crystal not

made

the sea any .

.

have

salt

All this solid matter has

fuller. .

increased in

;

for chemists tell us that

volume by the

therefore, started

Tins does not increase the

volume

.

been received into the interstices of sea water without swelling the mass

X.

salt

water

dissolves.

it

not

is

Here

up before us an economy of space

of

water,

is,

cal-

culated to surprise even the learned author himself of the

"Plm-ality of Worlds."

There has been another question raised which bears

upon what has ah-eady been said concerning the wliich, in the Iiave

'

•^

Condition of the Sea to

regidate

" Object ^

which, he maintains,

;"

Chapman, of

Toronto, communicated to the

on the Canadian Institute a paper ' ' intended

§

579

salts of the sea.

the 20th of January, 185.5, Professor

University College, °

the

578

sublime system of terrestrial arrangements,

been assigned to the

On

§

offices

To

evaporation."

of the Salt

Professoi

Chap^"""'^

theory on

is

" iniainly

establish

'i^e

ofthesalt-

this

nessofthe sea.

hypothesis, he shows,

by a simple but

the evaporation from

it

carefully conducted

the Salter the water, the slower

set of experiments, that ;

and that the evaporation which

takes place in twenty-four hours from water about as salt as the average

of sea water,

is

0.54


upon the wind. r

effect

with the trades very

Sand-

often,

and turn them

gular effect

and equatorial winds are common at

for westerly

;

winds.

Some hydro-

both these groups, in their winter time.

graphers have taken those westerly winds of the Society Islands to be an extension of the monsoons of the Indian

Not so they are local, and do not extend way eitlier from the Sandwich or Society Islands.

Ocean. great

:

That they are tion of sheet No.

about the former gTOup, an examina-

local 5,

a

North

Pilot Chart

Pacific, will instantly

show. §

812

It

is

a curious thing this influence of islands in the

of islands

tradc-wiud region upon the winds in the l

on

navigator

Influence Pacific

trade-

Every j

Pacific.

who has cruised in those parts of that ocean ^ "^ has often turned with wonder and delight to admire the _

winds.

gorgeous piles of cumuli, heaped up and arranged in the

most dehcate and exquisitely beautiful masses piles

found capping the

hills

among

tliat

Not only

possible for fleecy matter to assume.

it

is

are these

the islands, but they

are often seen to overhang the lowest islet of the tropics,

and even " a cloud

to stand above coral patches

by

and hidden

reefs,

day," to serve as a beacon to the lonel}'

mariner out there at

sea,

and

to

warn him

of shoals

and

dangers which no lead nor seaman's eye has ever seen or

sounded §

813

Clouds on

out.

These clouds, under favourable circumstances, gggn gathering above

low coral

tlie

island,

may

be

and performing;

theraeific, .

.

.

their office in preparing

.

it

in a very striking manner.

for vegetation

As they

and

fruitfulness

are condensed into

— THE WINDS.

34-7

showers, one fancies that they are a sponge of the most chapter

can

"

they

see, as

drop

but bountiful hand

down

would appear,

'-

their fatness," the invisible

aloft that is pressing

Maury's Sailing

out.

—

and delicately-elaborated material, and that he

exquisite

and squeezing

Directions, 7th ed.,

it

820.

p.

therefore, that these

desert countries

§

exercise a powerful influence in checking

and overcoming

No

the force of the north-east trade-winds.

There are no

It

814 exten-

fluences

check the

such extensive influences at

On

trades.

same

work checking

the south-east

the contrary, these are accelerated

south-east

for the

;

destroy the north-east trade-

forces that serve to

winds, or retard them, tend also to

draw the south-east Hence the

trade-winds on, or to accelerate them.

ability

of the south-east trade -winds to push themselves over into

the northern hemisphere.

Hence,

also,

we

infer that,

between certain

parallels of

latitude in the northern hemisphere, the sun's rays,

by

§

815

inference,

reason of the great extent of land surface, operate with

much more

intensity than they do between corresponding

parallels in

the

southern

;

and

mean summer temperature on is

higher than

south

it is

:

consequently, the

that,

shore north of the equator

a beautiful physical fact which

the winds have revealed, in corroboration of servations with the

thermometer

what ob-

had already induced

meteorologists to suspect. It appears,

from what has been the ° upon *

of the sun operating •^

which Plate

causes VIII.,

the

Now

monsoons.

arrows

it is

the rays

upon the water, ^ let

us

turn

to

The monmarked with half-bearded and half-

and examine into

soon regions are feathered

that

said,

land, not

;

and we

northern hemisphere, that

all

this

view.

perceive,

of Europe,

looking

some of

at

the

Africa,

most of Asia, and nearly the whole of North America,

§

816

cause of monsoonE.

THE PHYSICAL GEOGRAPHY OF THE

848

are to the north, or on the polar side of the north-east

c:iAPTER

—

SEA.

trade-wind zone

'-

whei'eas but a small part of Australia,

;

of South America, and

less

of South Africa,

less

still

are situated on the polar side of the zone of south-east

In other words, there are on the polar

trade-winds.

side of the south-east trade-winds

Australia,

in

summer enough

upon which

no

gi^eat plains,

except the

the rays of the sun, in

of the other hemisphere, can play with

force

to rarefy the air sufficiently to materially interrupt

these winds in their course.

But, besides the vast area

of such plains in the northern hemisphere, on the polar side of its trade-wind belt, the heat of

to

draw

these trade-winds back, there are

districts in the exti-a-tropical

summer heat

the

which

it

be not sufficient to

turn the north-east trade-winds back, and

their force, and,

may

numerous other

regions of our liemisphere,

of which, though

soon of them, yet

is sufficient^

make a mon-

be sufficient to weaken them in

by retarding them,

di'aw the south-east

trade-winds over into the northern hemisphere. §

817

Remarks on interferenceof land.

Now, as this interference from the land takes place infer, without appealing summer ouly, we miffht i t o ^

^j-^g

-^

'

'

of these trade-^vind ^ctual observatiou, that the position ^

zones

is

variable

;

that

that the equatorial edge of the

is,

south-east trade- wind zone

is

farther to the north in our

summer, when the north-east trades are most it is

§

818

in

to

in winter,

We

have

when they

uow wcak, now

goucs, a forcc

trade-wind

^vould causc thcsc zoncs

'

work upon

here, th.en, at

Fnrceat work on

feeble,

than

are strongest.

which, of course, strong, o' '

'

to

these trade- wind

vibrate

up and down the

Eou es.

ocean,

and within certain

of the year.

limits,

according to the season

These limits are given on Plate VIII. 1

§810.

2

§815.

for

— o^Q

THE WINDS.

chapter Durinospring ° the latter season these zones ^ ^ and autumn, XIV. , our in ana declination, northern extreme reach their .

spring their utmost limits toward the south.

Changing of

the

Monsoons.

—

Lieutenant Jansen, in

phenomenon

describes this "

We

§

819

work, thus

his appendix to the Dutch edition of this

J^^"^^^^°^,

'"^ °^

:

have seen^ that the calms which precede the sea-

breeze generally continue longer, and

with an upward motion of the air

;

that,

accompanied

are

on the contrary,

those which precede the land-breeze are, in the Java Sea,

generally of shorter dui'ation, accompanied

atmosphere; and that there

also

is

by a heavy

an evident difference

between the conversion of the land-breeze into the breeze

and

sea-

of the latter into the former.

Even as the calms vary, so there appears to be a § 820 marked difference between the changing of the monsoons ^~^^ As sea. in the spring and in the autumn in the Java Sea. "

soon as the sun has crossed the equator, and

its

vertical

rays begin to play more and more perpendicularly upon the northern hemisphere, the inland plains of Asia, North

and of North America, are so heated, as to give monsoons in the China Sea, in the North Indian Ocean, in the North Atlantic, and upon the west coast of Central America then the north-west mon-

Africa,

birth to the south-west

:

soon disappears from the East Indian Archipelago, and gives place to the south-east trade-wind, which east

monsoon

;

is

just as the north-west wind,

during the southern summer,

is

known

as the

which prevails

called the west

monsoon. 821

This is the only monsoon which is found in the , •! n 1 i.1 southern hemisphere, while in the northern hemisphere the

Monsoons

north-east trade-wind blows in the China Sea and in the

spheres.

"

.

•

1

'

1

§ 262.

•

1

§

in differ-

—

—

THE PHYSICAL GEOGRAPHY OF THE

850 CHAPTER Indian

Ocean

in the East Indian Archipelaf]jo tlie west

;

XIV.

_

monsoon

SEA.

prevails

and

;

when we find

here,

blows as the east monsoon,

the south-east trade

mon-

the south-west

soon in the adjacent seas of the northern hemisphere.

summer

Generally the westerly monsoons blow during the

months of the hemisphere wherein they are found. §

"

822

Winds de-

As

the land-breeze

"

stroy each

monsoon

otiier.

daily destroys in miniature the

regular flow of the trade-wind, so does the latter the west in larger

measure and observations will be able to ;

decide whether monthly disturbances do not also take place. §

823

"

Monsoons in Java

-^^est

Sea

it

dming

In the Java Sea,

monsooH blows

month

the

of February, the

almost contirmally

strong; °

"^

March

in

;

blows intermlttiugly, and with hard squalls

;

but in

April the squalls become less frequent and less severe.

Now

the chanoinoj commences.

spring up from ^

calms. clear

the east

All at once o-usts beo^in to

they are often followed by

:

The clouds which crowd themselves upon the

sky give warning of the combat in the upper

which the currents there are about to wage with each §

824

Electricity

"

The

driven

electricity,

thereby out of

channels, in which, unobserved, silently,

but with the

full

;

its

it,

now

sheen and

its

its

power, the

displays itself with

voice

with as-

fill

tonishment and deep reverence the mind of the so susceptible, in the presence of storm

impressions

that

inspire

feelings

sailor

and darkness,

both

of

by pretended occupations he

anxiety, which

natural

has been performing

consciousness of

mysterious task appointed to dazzling majesty

it

its

air

other.

dread

to

and

strives

in

vain to conceal* *

No phenomenon

dark tliuuder-storui

in nature in

makes a deeper impression upon the

a calm at sea.

Jansen.

sailor

than a

—

THE WINDS. "

Day aud

351

we now have

night

The

thunder-storms.

clouds are in continual

movement, and the darkened

laden with vapour,

in all directions througli the skies.

flies

The combat which the clouds seem to court and appears to

make them more

tunnel form,

them

tliirsty

to

when time and

quench their

thirst

dread

themselves

op[)ortunity

fail

to

—

'-

They

than ever.

extraordinary means to refresh

sort to

to

cuaptek

air,

:

|hu^f,(.,.

^^°™^

re-

in

allow

from the surrounding atmos-

phere in the usual manner, they descend near the surface of the sea,

and appear

their black mouths.

to lap the

water directly up with

Water-spouts, thus created, are often

""'atersiiouts.

changing

the

seen in

especially

season,

among

small

groups of islands, which appear to give rise to them.*

The water-spouts are not always accompanied by strong winds

;

frequently more than one

is

seen at a time, where-

upon the clouds whence they proceed disperse directions,

and the ends

finally causes

water which

them is

"

of the Avater-spouts bending over

to break in the middle, although the

now

suffered little or

in various

seen foaming around their bases has

no movement

laterally.

Yet often the wind prevents the formation of waterIn their stead the wind-spout shoots up like an

spouts.

§

82G

^^'""i-

spouts,

arrow, and the sea seems to try in vain to keep

The

sea,

lashed

into

fury,

it

back.

marks with foam the path

along which the conflict rages, and roars with the noise of

its

water-spouts

;

and woe

to the rash mariner

who

ventures therein If * I never saw more water-spouts than in the Archipelago of Bioun Singen, during the changing. Almost daily we saw one or more. Jansen. t The air-spouts near the equator always appear to me to be more dangerous

than the water-spouts. I have once had one of the latter to pass a ship's length ahead of me, but I perceived little else than a water-fall in which I thought to ojme, yet uo wind. Yet the water-spouts there also are not to be trusted. I

—

THE PHYSICAL GEOGRAPHY OF THE

352 CHAPTER

"

The height of the spouts

usually

is

SEA.

somewhat

le.su

than 200 yards, and their diameter not more than 20 ''

Height of spouts.

feet,

yet they are often taller and thicker

when

;

tlie

opportunity of correctly measuring them has been favourable,

however, as

tween the

it

generally

be accurately determined, higher than 700 ber, in the Duration

-^vest

ells,

have

I

never

nor thicker than 50

found them In Octo-

ells.

Archipelago of Bioun, they travel from south-

to north-cast.

minutes

was when they passed be-

islands, so that the distance of their bases could

They seldom

last longer

than

generally they are dissipated in less time.

;

they are going away, the bulbous tube, which

is

five

As

as pal-

pable as that of a thermometer, becomes broader at the base,

and

little clouds, like

steam from the pipe of a loco-

motive, are continually thro\vn off from the circumference of the spout,

and gradually the water

is

released,

cloud whence the spout came again closes

its

and the

mouth.*

have seen such spouts go up out of the water upon the shore, where they overthrew strong isolated frame-houses. I have, however, never been in a situation to observe in what direction they revolved. Jansen. * Miniature water-spouts may be produced artificially by means of electricity, and those in nature are supposed to be caused by the display of electrical phenomena. "From the conductor of an electrical machine," says Dr. Bonzano of New Orleans, " suspend by a wire or chain a small metallic ball (one of wood covered with tinfoil), and under the ball place a rather wide metallic basin containing some oil of turpentine, at the distance of about three quarters of an inch. If the handle of the machine be now turned slowly, the liquid in the basin will begin to move in different directions, and form whirlpools. As the electricity on the conductor accumulates, the troubled liquid will elevate itself in the centre,

become attached to the ball. Draw off the electricity from the conresume its position a portion of the turpentine remains Turn the handle again very slowly, ami observe now the attached to the ball. few drops adhering to the ball assume a conical shape, with the apex downward, while the liquid under it assumes also a conical shape, the apex upward, until both meet. As the liquid does not accumulate on the ball, there must necessarily be as great a current downward as upward, giving the column of liquid a rapid circular motion, which continues until the electricity from the conductor

and

at last

ductor to

13

nearly

let tlie liquid

all

discharged silently, or until

:

it is

discharged by a spark descending

—

—

;

THE WINDS. " Durin2f the

353

...

of the monsoons,

cliano-insr

.

cahn or

and

with

cool,

light gales

e-entle breezes,

from

all

Avitli

xi\'-

They

the chano-ini:^ o o

sails to

i.

However, the atmosphere generally becomes

winds.

and, contrary to expectation, the north-west

from a clear sky

Now

northerly.

wind

827

tiic

tea-

||,'g'^t|Je''

changes

m

monsooni

clear,

wind comes

about the coming of the monsoon

:

§

are

burning faces under the

clouded skies,* impatiently J trim the

the

mostly cnAPTER

varied with rain-storms

points of the compass.

harassing to the crew, who, >

it is

it is

the clouds are again packed together

but

dies away,

will soon be

it

come again from another

point.

waked

Finally,

up, to

the regular

land and sea breezes gradually replace rain and tempests,

The

calms and gentle gales. day, is

and in the Java Sea we have the

the east

up during the

east monsoon.

It

Farther to the south than the Java Sea

then May.

"

rain holds

monsoon commences

in April.

7

This monsoon prevails in September and October,

when

it

turns to

become the west monsoon.

It has

§

828

East monsoon.

seemed to

me

that the east

same in every month f that

into the liquid.

Tiie

latter liquid, the ball

If,

in this experiment,

will travel over its

its

direction becomes

more

same phenomena take place with oil or water. Using the must be brought much nearer, or a much greater quantity

of electricity is necessary to raise

"

monsoon does not blow the

we

miniature

let

sea,

it.

the ball swing to and fro, the

carrying

its wliirl[iools

little

water-spout

along with

it.

When

breaks up, a portion of the liquid, and with it anything it may contain, remains attached to the baU. The fish, seeds, leaves, &c., that have fallen to the earth in rain-squalls, may have owed their elevation to the clouds to the

it

same cause that attaches a few ties, to

di-ops of the liquid,

with

its particles

of impuri-

the ball."

* At sea the face and hands burn (change the skin) clouded than under a clear sky. Jansen.

much

quicker under a

•f- In the north-east part of the Archipelago the east monsoon is the rainy m^mEoon. The phenomena in the north-east part are thus wholly different from those in the Java Sea. Jaksen.

>

§851.

23

—

—

THE PHYSICAL GEOGRAPHY OF THE

So-t CHAPTER southerly,

and

its

power

SEA.

greater, after it has prevailed for

XIV.

some §

829

Effects of

time.''

" It is sufficiently

important to

fix

the attention, seeing

these circumstances have ° CTeat influence upon the winds iu the many straits of the Ai-chipelago, in which

tiiat

monsoon in straits of

*'

the Archi-

Especially in the

very strong.

straits to the east of Java, these cm'rents are I

have been unable to stem the current with eight-mile

However, they do not always flow equally

speed.

They

nor always in the same direction. strongest

when

straits durino; the east

north,

'

iQn.

and

east monsoon,

Chanseof monsoons on Java

"

As

said that the cm-rents in the

monsoon run eighteen hours

and

the sea

It is

and the reverse during of the meridian

by

the

is

probable that the heated water

discharged to the north during the

to the south during the

makes the coming

j^^Q^yn to the inhabitants of the

of the east

to the

to be the fixed point of time for the turn-

of the Archipelago

830

is

The passing

ing of the currents.

§

It

six hours to the south,

the wcst mousooiL

moon appears

strong,

are probably the

the tidal current and the equatorial cur-

rent meet together.

Mnnnpass-

.

.

_

strong currents inin most of the time.

peiago.

monsoon

west monsoon.

of the southern

summer

Java coast.i the turning o '

into the west

'

monsoon commences.

coast.

After the sun has finished hemisphere, and brings •

As

is

its

its

yearly task in the northern

powerful influence to operate

well known, the Strait of Soerabaya forms an elbow whose easterly

outlet opens to the east, while beginnin;;; of the east

tlie

westerly outlet opens to the north.

monsoon the sea-winJ

(east

westerly entrance as far as Grissee (in the elbow)

;

In the

monsoon) blows through the in the latter part of this

mon-

soon, the sea-wind blows, on the contrary, through the easterly entrance as far

as Sambilangan (the narrow passiige where the westerly outlet opens into the sea). •j-

tlie

Janskn.

In the Archipelago we have generally high water but once a day, and. with equinoxes, the tides also turn. The places which have hi^h water by day in

one monsoon get

it

at night in the other.

Jaksen.

THE WINDS.

8.55

a chanci;e in the southern hemisiihere, ^ '

is

chaptkb at once ])erceived ^ XIV.

in the constant fine weather of the east

Java

As soon

Sea.

Sea

and

in the upper

to resist the

north-west

Upon and

less

seem to have

make

and west,

over from

definitely if

known.

superioiity

their

in the neighbourhood of

The atmosphere, alternately

appears as

sufficient strength

aggressors, who, with wild storms from the

storms occur, but at sea they are

more

so continuous.

atmosphere appears to be

the south-east trade, which has blown as the

;

east monsoon, does not

"

height upon the Java

The calms then are not

spring tm-ning.

violent

its

accomplished much more rapidly than the

is

The combat

at

is

it

tlie

then the true tui-ning of the monsoon

(6° south),

begins,

as

monsoon of

the land, thunder-

less frequent.

clear

the

and cloudy, moves

north-west,

§

831

it *f"^e'"eiit

that

so

no combat were there waged, and the south-

spue-.e.

east gives place without a contest. " The land-breezes become less frequent, and the pheniolit become, in a certain sense, nomena by J and by J o J day Storms of wind and more accordant with each other. '

^

§

832

^'^'^''^-

breezes

^

'ess fre-

quent.

rain beneath a clouded sky alternate with severe gales

and steady winds.

monsoon "

is

In the

last of

November

the

west

permanent.

Such are the

shiftings.

But what have they

to

do

with the general system of the circulation of the atmos-

§

833

wimtthe '•shift-

pliere .

Wlienever we

?

read

attentively

the

beautiful

meditations of the founder of the Meteorology of the c


the month, and from the course upon which he to

make an

scores,

will

thus

make

entry, he has (||||).

the

fifth

;

is

about

akeady made fom' marks

or

The one that he has now to enter and he " scores and tallies," and so

on, until all the abstracts relating to that part of the

ocean upon which he

is

at

his materials exhausted.

work have been gone These "

fives

and

over,

and

tallies" are

exhibited on Plate V. §

932

neference to Plate V.

Now, with tliis explanation, marked A (Plate V.), ^ ''

district

it

will be seen that in the

there have been examined

the logs of vessels that, giving the direction of the wind for every eight hours,

to enable

me

have altogether spent days enough

to record the calms

and the prevailing

tion of the winds for eight hours, 214-i times

285 were

for the

month

of September;

observations for September the wind

is

:

direc-

of these,

and of these 285 reported as

pi-e-

407

STORMS. vailing for as

8 times

as eight hours at a time

from N.N.E.,

;

];

E.S.E.,

much

S.W, 93

;

N.N.W.,

1

S.E.,

4;

Calms, 5

;

;

2

N.E.,

;

;

E.N.E.,

1

chapter

E,

;

25; S.S.AV., 45 W., 47 W.N.W., 1 7 N.W, 15 total, 285 for tins month in tliis 2;

S.S.E,

W.S.W., 24. ;

1

from N.,

:

S.,

;

;

—

district.

The number expressed

number

of observations of calms and winds together that

month and

are recorded for each

In

C, the

west.

But

wind in A,

May

in

which

district.

one-third of the time from

sets

between the same

is

the favoui'ite quarter for the same to south-west, the

wind

;

or,

month

is

parallels,

from

§

934

'^^'"'J'n

soutli

setting one-third of the time for

that quarter, and only 10

west

whole

in figures denotes the

on the average,

out of 221 times from the it

blows from the west only

I3 day during the montli of May.

In B, notice the great

"

Sun Swing"

of the winds in

September, indicatino; that the chano-e from winter, in that region, ° to summer, gentle

In some

is

sudden and violent

;

'

summer

to

from winter

§

935

"^"" "''"'i» '"

September

and gradual.

districts

of the ocean,

more than a thousand

Number

of

otiserva-

observations have been discussed for a single

month

whereas, with regard to others, not a single record

be found

in

is

;

tions

made

to

any of the numerous log-books at the National

Observatory.

Typhoons.

—The China Seas

furious ° (jales of wind,

'

and white

squalls.

are celebrated for their

known among » seamen

as typhoons ''

J-

These seas are included on the plate

(VIII.) as within the region of the

Ocean.

monsoons of the Indian But the monsoons of the China Sea are not five-

month monsoons;^ they do not

prevail from

south for more than two or three montlis, '

§ 788.

tlie

west of

§

936

Typhcnna in Chins ^''^

408

THE PHYSICAL GEOGRAPHY OF THE

SEA.

Plate V. exhibits the monsoons very clearly in a part

CHAPTKR XVII

In the square between 15° and 20° north,

of this sea.

§937 110° and 115° ilonsoona as exhiliitert

on

Plate V.

monsoons ber,

;

east, there

that

is,

appears to be a system of three

one from north-east in October, Novem-

December, and January

April, changing in

in June, July,

;

one from east in March and

May and

another from the southward

;

and August, changing

in September.

The

great disturber of the atmospheric equilibrium appears to Arid plains

bc situatcd

01 Asia.

among the °

arid plains of Asia '

their influence

;

^

extends to the China Seas, and about the changes of the

monsoons these awful

gales, called

typhoons and white

squalls, are experienced. §

Time

In

938 of

like

manner,

Mauritius

the

hurricanes,

or

the

Mauritius hurricanes

cyclones of the Indian Ocean, occur duiina: O the unsettled state of the atmosphcric equilibrium which takes place at

cyclones of Indian

that debatable

Ocean.

tradc-wiud

'

•'

period during the contest between the

,

and the monsoon

force

force,'

and which

debatable period occurs at the changing of the monsoon,

and before ascendency.

either force has completely gained or lost the

At

this period of the year, the winds, break-

ing loose from their controlling forces, seem to rage with

a fury that would break up the very fountains of the deep. §

939

West and Last India hurricanes

So, too, with the TlicsB

West India hmricanes

of the Atlantic.

wiuds are most apt to occur duriufj the months of ^ =>

August and September.

There

is,

therefore, this

remark-

able difference between these gales and those of the East

Indies

:

the latter occur about the changino- of the

soons, the former during their height.

mon-

In August and

September, the south-west monsoons of Africa" and the south-east monsoons of

1

§ 796.

the

»

West

§ 810.

Indies'* are

«

§ 737.

at

their

409

STORMS. heiojlit

tlie

;

aoent of one drawinnj the noiih-east trade-

winds from the Atlantic into the interior of

New

ohapteii XVII

Mexico

'

and Texas, the agent of the other drawing them into the interior of Africa. directions, assist

two

Its

forces,

now and then

pulling in opposite

to disturb the atmospheric

equilibrium to such an extent that the most powerful revulsions in the air are required to restore

The hurricane season

"

says Jansen, " occurs

monsoons

and

;

in the

it.

North Atlantic Ocean,"

simultaneously with

in the

the African

same season of the year

which

in

§

940

Jansen's

remarks on imnicaiies

the monsoons prevail in the North Indian Ocean, in the

China Sea, and upon the western coast of Central America, the seas of the northern hemisphere have the hurri-

all

On

cane season. has

its

the contrar}^, the South Indian Ocean

hurricane season in the opposite season of the

and when the north-west monsoon prevails

year,

in

the

East Indian Archipelago. "

In the South Pacific and in the South Atlantic, so

far as I

know,

i-otatory

storms are never known, and these

§

941

^°"!'^ i iiCltlC

seas

have no monsoons.

Such a coincidence of

liurricanes

''"''

so""*

.\tlantic

with monsoons, and of the hurricane- season with the monsoon-season,

is

not without signification.

It ever gives

rise to

the thought that the one disturbance causes the

other

and however

;

terrible the hurricanes

may

be to

us,

however disastrous they may appear, yet we are compelled to

acknowledge therein the healthful workinf; of Nature,

wliich

compensating over

is

all

and in

all.

We

need

doubt that these revolving: o storms have a determinate task to perform in the economy of nature n(^t,'

-

—a

then, '

task which they cannot otherwise

rotations

;

and certainly

it is

fulfil

save

by

good that they restore iu

^^^o'^"*? storms.

THE PHYSICAL GEOGRAPHY OF THE

410

CHAPTER proportion to

—

the

power

terrible

SEA.

wlierewitli

they are

XVII.

§

"

942

ofiiRhtiiiiiff

intrusted.

We

know

do not

all

tlie

which are

disturbances

caused by the land in the condition of the atmosphere.

and

thunder.

'

Ths way

of the lightning of the thunder'

The

unknown.

is

to us all

circulating channels of electricity are as

yet hidden in a deep night. §

943

Remarks on tlie nsesof

"

know what

Neither do Ave

influence the land

^varm currcuts in the sea have thereon,

know

—even

less

and the than we

wluit Operations are appointed for the hurricanes in

liunicanes

the

economy of nature

;

but that they, in their way, have

The

important services to perform, cannot be doubted.

almighty and merciful Wisdom,

whom we

find universally

—

in all the operations of nature, assures us thereof

us a pledge.

The

their feet in

warm

prevail to arise

warm

water, and that in

water currents

work

where they

which appear

solid crust of the

of the waters of the

reiri^lar flowincj

us to suspect that there

between the hurricanes and the warm

seas

all

settled currents are also found,

earth causes in the

jrnnicanes and

to

fact that the hurricanes prefer to place

from the disturbance which the

sea, causes

is

is

a certain relation

warm

currents

;

and,

economy of nature the hunicanes in the atmosplicrc and the warm 'rivers in the sea' work finally,

that in the

•'

together to restore the disturbed equilibrium in nature,

together.

m

which can be done

no other

the wa}^ which they, as

Thus we

together.

follow surface,

side

the

most

it

way than

this,

and along

were, mutually agree to follow

see the hurricanes

prevailing

beyond the

current of

air

tropics

along

the

on one side from the south-west, on the other

from the north-west

to the north

and

east,

;

just as the Gulf Stream flowf^

and the warm currents of the South

411

STORMS.

Indian Ocean to the south and current to the north and east.

by which

universal laws

touching "

is

their

1

latitude

we

In this matter

all

is

the China chapter XVII.'

the

see, again,

governed

:

very-

the simplicity of the divine plan.

When

upon

east, and, again,

the

way ./

hurricanes and the to the poles, i

'

which the upon *

'

rivers

in

have reached the

effort of the

the

sea,' §

parallel of i

diurnal revolution

of the earth upon her axis causes air and water to

be

944

^*'"'^'^'

"^

diuinal resolution of the earth

"P"" "« axis.

forced in a north-easterly or south-easterly direction, then

bow

they

themselves submissively to the law, and go

together, often tasks.

hand

And now,

in hand, to accomplish their appointed if

we suppose

revolution everything which this parallel east,

then

of

it is

latitude

is

that by the diui-nal moves from the equator to bent more gradually to the

remarkable that the

first

part of the course

of circulating storms often stands perpendicular to these

supposed movements of the

air,

Ocean runs nearly W.N.W.

;

and

in the

in the

North Atlantic

South Indian Ocean,

W.S.W. " Hui'ricanes

are sometimes observed upon the limits

and upon the

of the African monsoon,

soon of the

East Indian

limits of the

Ai-chipelao^o. i o

mon-

In this Archi-

pelago huiTicanes or right heavy spouts are seldom seen,

However, hurricanes have been observed in the southern hemisphere, between 88° and 90" east longitude. They are also found in September in 13° north latitude

and

29° west longitude, and in 16° 83' north latitude and 24;° 20' west longitude the latter also in 18° north latitude and 25° west longitude, and in 16° 30' north latitude and 26° 40' west longitude;* yet not the mon;

m

*

KetHleW.

§

945

,^i)^e^.ehu'^

P'^''"f have been o^^ei-ved.

412

THE PHYSICAL GEOGRAPHY OF THE

—

CHAPTER soon xvir.

.

SO

much

.

is

known

limits

;

to

me

—but

.

,

SEA.

ricrlit

upon

its

.

in the equatorial belt which wavers about

also

the monsoon, and which becomes narrower and narrower as §

"

946

Combats in the air conse-

recedes from the equator.

it

Now, when we remember what

is said' '

^

tlie

of the spring

with southern hemisphere, which agrees 1 o » autumnal changino; in the northern hemisphere, and

chanffincf o in the

^

quent on the changing

think of the combat which

of spring

between the various currents of

and autumn,

spouts whicli arise in the East Indian Archipelago

,

.

.

.

is

then so manifestly waged air

and the numerous

we

aid of small groups of islands, then

prised to find a similar effect produced

when

the African monsoon, especially torial belt of

Yerd

When we

tlie

;

limit of

pushes the equa-

take into account that this belt

becomes narrower and narrower as

draw

shall be less sur-

upon the

calms quite over to a portion of the Cape

Islands.

the equator

it

by the

it

is

removed from

that also the different currents of

air,

in opposite directions, lie closer to each other

which that

;

south-west and north-west winds approach very near

to each other,

and that the

in

latter,

August and Sep-

tember, are deflected out of their course by the heights Cause of

^f

^^j^g

Cape Verd Islands

;

—then

not

much more

why

sary to enable one to comprehend

is

neces-

a wind whicli,

coming from the north-east, and veering by the around to the north-west, should, as

it

nortli

meets the south-

west winds, make a complete revolution, and in so doing

form a whirlwind, which would go travelling through the north-east and south-east trade-winds, especially

when

the moistui'e and electricity of these air-currents are ferent,

as

is

generally the case.

the north-east trade-wind, as *

it

§820,

And

dif-

seeing also that

draws more and more

413

STORMS.

toward

north,

tlie

monsoon,

it

may

lies

south-west chapter

tlie

why

be readily conceived

the motion

'

be from the right hand to the

of this whirl should left,

the left of

to

movements of the hands

or contrary to the

of a

watch. "

Thus,

circular

when upon

the limit of the African monsoon a

motion in the

situation of the currents of other, that the

the

left.

we may

air arises,

movement

air, .,,

and

their relation to each

from the right side to

will be

hand

For the same reason, the motion to the right.

way

;

south-west turned back south-east,

north-west monsoon.

Therefore,

is

left

hand

motions of the winds circum-

from the find the

the south-east, or the to the left of the

is

when

a circular motion

there takes place upon the limit of the monsoon,

go from the

947

circular

in the soutli-

Near the north pole we

cui'rents of air just the other

§

in various

„

,

ern hemisphere, in the South Indian Ocean, left

from the

infer,

it

must

to the right, or with the hands of

a watch, "

The want of knowledge prevents me from venturing

to penetrate into the

'

hidden chambers out of which the

§

948

^mpossibillty of

^

whirlwind comes,' for the circulation of the atmosphere

anivingat definite

must, like the revolutions of

human

society, bring all tlie

conclusions.

natural forces

into commotion,

and

they,

in

the strife

which they wage, become renewed and strengthened to perform their appointed work for the universal welfare,

and pass away accomplished indeed, I

—

is

its

may

violent,

like the all-destroying meteor, after

terror-awaking mission.

call

The

having

strife

—

if,

the opposite workings in nature strife

terrible.

The monsoon has attained

greatest strength, the disturbance

the atmosphere has reached

its

its

in the circulation of

utmost

limits,

the vapour

— THE PHYSICAL GEOGEAPHY OF THE

414 CHAPTER

and the heavy clouds act

in

harmony no

SE.\.

longer,

and with

XVII, '

wild violence the uproar, nursed in

way

'The

silence,

breaks

forth.

for the lightning of the thunder' appears to he

broken up.

§949 Humsoutii

Indian Ocean.

In the South Indian Ocean (25° south

"

latitude), a

was observed,* by which several of the crew were made blind, others had their faccs cut opcu, and those who were in the rigging had The master of the ship their clothes torn off from them.

hurricane, accompanied

compares the sea with snow.'

by

hail,

to a hilly landscape in winter, covered

'

Does

not appear as

it

the

if

treasures of

'

the hail' were opened, Avhich were 'reserved against the

§

950

Furious

time of trouble, against the day of battle and war?' "f In the extra-tropical regions ExTPvA-TEOPlCAL Gales.

—

of

each

hemisphere furious gales of wind also occur.

gales in

the extra-

Quc

.

of thcsc, remarkable for

its

violent effects,

was en-

tvopical

regions,

Wreck,

countered on the 24th of December 1853, about three

hundred miles from Sandy Hook, latitude

39° north,

longitude 70° west,

steam-ship.^

by the San Francisco

That ship was made a complete wi-eck

and she was abandoned by the

by the

nell),

§

951

F.xtract

"

flie

"Eagle

Wing

from Boston to San Francisco.

tudc 62° 32' west.

after

(Ebenezer H. Lin-

She encountered the

and thus describes

Decemher 24, 1853.

from log of

Some months

California mail the abstract

log of the fine clipper-ship Eagle

ill-fated steamer's gale,

few moments,

survivors, after incredible

hardships, exertions, and sufferings. this disaster, I received

in a

— Latitude 39°

it

:

15' north, longi-

First part threatening weather

^

I

:

short-

\

, ^j

mn]m, Captain Brandlijrt. + Natuurkiimlige Bescliryving der

Zeeen, donr M. F. Maury, LL.D., Luitenant der Nord Amerikaansche Marine, vertaald door M. H. Jansen, Luitenaut ter Zee.

Dordreciit, P.

K. Braat, 1855.

>

ssa.

—

— STORMS.

ened

sail.

the courses.

At 4 At

p.ji.

415

close-reefed the top-sails

and furled

chapter

8 p.m. took in fore and mizzen top-sails;

'

hove to under close-reefed main top-sail and spencer, the lying with her lee rail under water, nearly on her

sliip

At

beam-ends.

30

1

masts went over the

At

bowsprit-cap. I

my

In

mam

a sea took away jib-boom and

;

thirty-one years' experience at sea,

have never seen a typhoon or hurricane so

two men overboard

my

;

top-gallant-

blowing a perfect hurricane.

side, it

8 A.M. moderated

and

A.M. the fore

saved one.

Lost

severe.

Stove sky-light, broke

barometer, &c., &c."

Severe gales in this part of the Atlantic polar side of the calm belt of Cancer '

the months of June,

Jid}^,

—

i. e.,

on the

occur duringo August, and September. This rai-ely ./

appears to be the time wlien the fiends of the storm are

952

§

"^''^ewiien

severe sales sel-

dom

occur

in particular part of

most busily at work in the West

Indies.

During the

remainder of the year, these extra-tropical

gales, for the

most

part,

come from the noi'th-west

the most famous season for these

time

when

;

but the winter is

is

tlie

the Gulf Stream has brought the heat of sum-

mer, and placed

it*

cold of the north

;

in closest proximity to the extremest

and there would,

therefore, it

seem, be a conflict between these extremes great disturbances in the cold to the

That

gales.

Atlantic.

air,

;

would

consequentl}',

and a violent rush from the

warm.

In like manner, the gales that most prevail in

953

tlie §

extra -tropics of the southern hemisphere come from the pole

and the

west,

i.

e.,

south-west.

Storm and Rain Charts ah-eady been published for the

for the Atlantic

Ocean have

by the Observatory, and

whole seas are in process of construction.

§

954 ^"'^

others

The __^____.

KaT SeTtilntic.

4

THE PHYSICAL GEOGRAPHY OF THE

6

1

show the

CHAPTER object of such charts is to

frequency of gales in

frequency of calms, What

^]^rj^ i^r^lf

charts

covers the northern hemisphere ^

Bhow.

;

and

rela-tive

the relative

thunder, and lightning.

fogs, rain,

They show that

These charts are very instructive.

955

§

directiotis

parts of the sea

all

SEA.

Qf Q^Q atmospherical coating of the earth

—

we may

if

-^

which

take as a

type of the whole what occurs on either side of the equator in the Atlantic dition than that §

There

956

Rain storiBsand

Mims

in

North and South Atlantic.

morc

are, as

calms, '

Ocean

—

in a

is

which covers the a

more

more

rule, fosfs,'

o

much

rains,

more gales

and more thunder and

North than in the South Atlantic.

in the

con-

less stable

soutliern.

of wind, lifchtnino-, o o'

These pheno'

mena, at equal distances from the equator north and ^ ^ _

south,

—

and

that

for all

is,

every 5° of latitude, have been compared

the storms, calms, rains, &c., between the

parallels of 25° and 30° north,

for instance,

compared with the same between the 80° south

;

;'

have been

parallels of 25°

and

those for January north being compared with

those for January south, and so on for each month, be-

tween

all

the five degree

(5°,

10°, 15°, &c.) parallels

from

the equator to 60°, north and south. §

957

t^onT eases.

In some places here and there, and in some months

^^^ ^^^

then, there

may

be more

gales, as in the neigh-

bourhood of Cape Horn, in the South than in the North Atlantic

;

but such cases constitute the exceptions, they

by no means the rule. Cape Horn in the South Atlantic, and the Gulf Stream in the North, furnish seats are

for agents whicli are very

marked

in their workings.

This

Plate brings out the fact that, as a rule, rains and calms go

together in the tropics; but beyond, rains and gales are

more apt

to occur at the

same time, or 1

Plate XIII.

to follow each other.

— 417

STORMS.

With regard to the disturbing agents which are let loose from Cape Horn and the Gulf Stream upon the atmosphere, I

beg leave to quote a remark of Janseu's

"In contemplating Nature in her universal which

all

is

aspect, in

with

"•

mutual kindness suppoi't each other by the complaisant interposition of air

—

XVII.

:

ordered that all the parts so perfectly " '^

chapteb

and water, we cannot possibly

reject

§

958

Jansen-s

remarks "nfiis-

agents loose

the idea of unanimity of action

;

that when, impeded or prevented

bond of union

their

is

shown

so

little,

by external

local causes,

broken, then are observed the

ten-ible efforts of Nature, is

and we may conjecture

by which

its

almighty power

which we know

in combating that disturbance of

and in renewing and perfecting those broken

bonds.

Forces which are otherwise working beyond the

reach of

human

vision then

come

the earth to tremble to her centre, and

anxious and dismayed.

is

for

They cause

man

to stand

Yet Omniscience watches, a Pro-

vidence cares, and the Almighty

land that

combat

forth in the

the restoration of the disturbed equilibrium.

The

is love.

given us as a dwelHng-place

is,

delightful

at the

time, the cause of all the disturbances in the air

same

and in

the ocean, whence the hurricanes and the 'rivers in the sea'

arise,

which in tm-n are

for

the

universal good

;

where they are not found, we may be certain that the cuiTents of the air and of the water

harmoniously together.

And

is

work undisturbed,

not this th^ case in the

south-east trade-wind of the South Atlantic Ocean ?"

27

let

upon

tiieatmo-

4

J

THE PHYSICAL GEOGRAPHY OF THE

8

CHAPTER

SEA.

XVIII.

ROUTES.

—

How closely Vessels follow each Passages have been Shortened, § 959. Track, 961.— The Archer and the Flying Cloud, 962. The great

How

otlier's

Race-course upon the Ocean, 964.

— Description of a

Knowledge of the Winds enables the Navigator

CHAPTER

The

to

Ship-race, 966.

compute

— Present

his Detour, 991.

principal routes across the ocean are exhibited on

XVIII.

Plate VIII. §

959

the oreai end and aim of

;

.

.

aU

this labour

and n

•

,

.

The great

^search are in these, and consist in the shortening of

eli'rtonhe

P^^sages

authov-3

hibouiS

and

'*"'^'''^" re-

searches.

last,

—

the

improvement of navigation.

and other

terests

in the

objects are

mind

habits of thought Avhich

we

live as

of a practical people, who,

and modes of eminently

in relief half so grand

lifted up, as

ther, for the ?

9G0

We

A.iv,,Ti-

-winds

knnwiedge ot winds and cur-

Qccan.

action,

utilitarian,

and imposing

ments by which the distant have been

Other

it

in-

promoted thereby, but these

isles

mark

by

their

the age in

do not stand out

as do those achieve-

and marts of the sea

were, and brought closer toge-

convenience of commerce, by

many

days'

sail.

have been told in the foregoing pages how the

blow and the currents flow

in all parts of the

Tliesc control the mariner in his course

kuow how

to stcer his ship

on

this

and

;

to

or that voyage so as

rents.

always to make the most of them,

is

the perfection of

The figures representing the vessels are marked as to show whetlier the prevailing direction the wind be adverse or fair. navigation.

§

9G1

p.iiuiar

When

so of

one looks seaward from the shore, and sees a

ship disappear in the horizon, as she gains an offing on a

voyage

to India,

or the Antipodes perhaps, the

common

EOUTES. idea

that

is

slie

41

bound over a

is

trackless waste, •

1

and the

chapter xvin.

•

•

1

1

chances of another ship, sailing with the same destination the next day, or the next week, coming- up and speaking

her on the "pathless ocean," would, to most minds,

vv'ith

'^

Yet the truth

seem slender indeed.

the winds and

is,

winds ami currents ^le gnidei to the

now becoming

the currents are

that the navio-ator, like the

backwoodsman

maimer.

in the wilder-

enabled

ocean

not indeed upon

"to blaze his way" across the

ness, is ;

be so well understood,

to

literally

trees, as

in the wilderness,

The

upon the wings of the wind.

but

of scientific

results

inquiry have so taught him liow to use these invisible couriers, that they,

with the calm belts of the

him the

as sign-boards to indicate to

tarnino;3,

air,

and

serve forks,

and crossings by the wa}^ Let a ship next week

New York

from

sail

let

many

each other's path ^

times,

"^

before me.

It

:

and the

they will cross ''

Thus a

case in point

to see bound

happens to

They was

Flying Cloud on a recent voyage to California.

New York

California-bound

and

so

other.

But the Archer had

day

that

after

the

sailed

Flying Cloud put to

was the Archer, but without reference

sea,

to each

The Archer, with Wind and Current Charts

alonor the

trades

it

She was runnino- against time,

also.

way across the calms new route, down throusfh the

hand, went blazing her

and

to

the equator

;

in

of Cancer, north-east

the Cloud followed after, cross-

ing the equator upon the

trail of

Thomas

of the Arciier.

Off Cape Horn she came up with him, spoke him, handed luui the latest

for

the Archer and the

are both fine clipper ships, ably commanded.

from

962

caseoftwa vessels

and are almost sm-e

the case of

is

not until the ninth

§

CaUfornia.

each other by the way.

be

to California,

a faster one follow after

New York

dates,

and invited him

to dine

^^''^,j'"J®'

""'"•

— 420 CHAPTER

THE PHYSICAL GEOGRAPHY OF THE

on board the Cloud Archer,

§

963

Result of

thevoy-

" I

was

;

" Avliicli

invitation," says he of the

\

reluctantly coinpelled to decline."

The Flying Cloud finally ranged ahead, made her and disappeared among the clouds that lowered npon the western horizon, being destined to reach her adieus,

.

ages.

SEA.

.

port a week or more in advance of her Cape Horn consort. Though sighting no land from the time of their separation until they gained the offing of

—

or eight thousand miles off

were so nearly the same, IX., they §

This

964

Tiie great

race-

is

San Francisco

the tracks of the

that,

would appear almost

two

six

vessels

being projected on Plate as one.

the great race -course of the ocean

Some

tliousaud milcs in length. *

—some

;

it is fifteen

of the most ° g-lorious

_

course of the ocean.

tnals of ppccd witnessed,

and of prowess that the world ever

among

taken place over

it.

sliips

that

"walk the

Here the modern

waters," have

clipper ship

—

the

work that has ever come from the hands of man has been sent, guided by the lights of science, to contend

noblest

with the elements, to outstrip steam, and astonish the world. §

965

ihtfrTce*^ ofi&52.

The most celebrated and famous off upon this course

been run came Qf 1852,

when

ship-race that has ever :

it

was

in the

autumn

navigators were beginning fully to reap

the benefits of these researches with regard to the winds

and

currents,

and other

geograpliy of the

sea,

ships put to sea from

that four splendid

New

time, tliey presented really a

names of these noble

— the

new

clipper

York, bound for California.

They were ably commanded, and at Sandy Hook, one by one, and Tlie

with the physical

facts connected

as they passed the bar at various intervals of

most magnificent

ships

and

Wild Pigeon, Captain Putnam

spectacle.

their master were, ;

the

John

Gilpin,

;

ROUTES.

Captain Doane

—

Captain Nickels

alas

421

now no more

!

;

the Flying Fish, cHAPTEa

and the Trade "Wind, Captain Webber.

;

know

Like steeds that

were handled

their riders, they

with the most exquisite

'

and judgment, and in such

skill

hands they bounded out upon the "glad waters" most

Each being put upon her mettle from the

gracefully.

was driven, under the seaman's whip and

start,

speed over a com'se that

full

spur, at

would take them three

it

long months to run.

Wild

The Gilpin,

Pigeon

29

October

;

October

sailed

the

Flying Fish,

and the Trade Wind, November

studied

make time

;

9Gn

was the season

It

14.

§

'^^^^''''

Each one was provided with the

for the best passages.

Wind and

12; the John November 1

Current Charts

them attentively

;

;

each one had

evidently

and each one was resolved to

the most of them, and do his best.

All ran against

but the John Gilpin and the Flying Fish for

;

the whole course, and the Wild Pigeon for part of

it,

ran neck and neck, the one against the other, and each against

all.

It wtis a

sweepstake with these ships around

Cape Horn, and through both hemispheres.

Wild Pigeon

led

New

other two out of

tlie

one by seventeen, the other by twenty days.

and chances of the winds seem from the she

fell

gale,

start.

As soon

as she

to

York, the

But luck

her have been against "

had taken her departuie,

into a streak of baffling winds,

and then into a

which she fought against and contended with

week, making but a time of

it

little

in crossing the horse latitudes.

been nineteen days thirteen of

progress the while

them

out,

she had logged

as daj's of calms

and

;

for a

she then had

After having

no

less

baffling

than

winds

§

967

Tiiestmt '"^^'''''

Pigeon."

422

THE PHYSICAL GEOGRAPHY OF THE

had brought her no farther on her way than the

CHAPTER these XVIII. '

parallel of fine

SEA.

26° north in the Atlantic.

run to the equator, crossing

it

between 33° and 34°

She was unavoidably

the thiity-second day out.

w^est,

Thence she had a

west for only two days before, 30° 5° north in an excellent position, she crossed forced to cross

§

968

Testimony of Captain

Pollard.

so far

it

;

—

In proof that the Pigeon had accomplished

that

all

her would permit, gkiU could do, and the chances against ^ y^TQ have the testimony of the barque Hazard, Captain '

'

This vessel, being bound to Rio at the same

Pollard.

The Hazard

time, followed close after the Pigeon.

hand with the charts

old

;

she had already

voyages to Rio, with them for her guide. longest of the six, the

and a half 34°

of which

by compulsion, having

30', also

six

This was the

was twenty-six

line this

time in

crossed 5° north in

But, the fourth day after crossing the equator, she

31°.

was

mean

She crossed the

days.

an

is

made

clear of

Cape

St.

Roque, while the Pigeon cleared

it

in three days.* §

9G9

Better fortiineof

So

far,

had turned up against the

therefore, chances

Pigeon, in spite of the skill displayed

tlie

otiier ves-

by Putnam

as a

na\ngator, for the Gilpin and the Fish came booming

gela.

along, not under better

management, indeed, but with a

better run of luck and fairer courses before them. this stretch

they gained upon her

the Fish ten days

;

so that

In

— the Gilpin seven

now

the abstract logs

and

show

the Pigeon to be but ten days ahead. §

970

Course the of " Fish.

Evidently the Fish was most confident that she had the

lieels

of lier competitors

was proud of

it

;

;

she

felt

her strength, and

she was most anxious for a quick run,

* AccorJiug to the received opinion, this

was impossible.

ROUTES,

and eager withal

for a trial.

423

She dashed down south-

chapter

wardly from Sandy Hook, looking occasionally at the charts

but feeling strong in her sweep of wing, and

;

judgment of her master, she

ti-usting confidently in the

kept, on the average,

noble and fine

crowded on her canvas

trusting quite as

performed

to leeward of

many

Rejoicing in her

the right track. qualities, she

two hundred miles

much

to its

utmost

stretcli,

and

to her heels as to the charts,

the extraordinary feat of crossing, the sixteenth

day out from

New

York, the parallel of 5° north.

The next day she was well south

of 4° north,

and

in

§

971

the doldrums, longitude 34° west.

Now

for Fortune seems to her heels became paralyzed, ' "

have deserted her a while, winds

power

failed him, feared so ;

they were

by them. St.

— ;

at least her master, as the

fovfune seems to '^« " Fisli."

^"''

they gave him his motive

and he was helplessly bafHed

fickle,

The bugbear of a north-west current

off

Cape

Roque^ began to loom up in his imagination, and to

look alarming

upon him

;

;

then the dj*ead of falling to leeward came

chances and luck seemed to conspire against

him, and the mere possibility of finding his fine ship

back-strapped

filled

tlie

mind

of Nickels with evil fore-

He

bodings, and shook his faith in his guide.

doubted

the charts, and committed the mistake of the passage.

The Sailing Directions had cautioned the again and

ward

.

airain,

,

in the equatoiial

would himself engage airs,

navigator,

to fan along to the eastnot to attempt ^

doldrums

;

for,

so doing, he

with baffling

sometimes re-enforced in their weakness by westerly

currents.

But the winds had

failed,

and

so

too,

the

smart captain of the Flying Fish evidently thought, had '

§ 470.

972

tain's

.

by

in a fruitless strife

§

Thecapp'eat mis-

THE PHYSICAL GEOGEAPHY OF THE

424f

'

all

They advise the

Sailing Directions.

CHAPTER the

SEA.

navigator, in

such cases, to dash right across this calm streak, stand

boldly on, take advantage of slants in the wind, ami,

by

make

this device,

easting enough to clear the land.

So, forgetting that the charts are

rience of great

founded on the expe-

numbers who had gone

before him, Nickels,

being tempted, turned a deaf ear to the caution, and flung SiWdy three whole days, and more, of most precious time, dallying in the doldrums. Time

He

lost.

and

Spent four days about the parallel of 3° north,

his ship left the doldi'ums, after this

waste of time,

nearly upon the same meridian at which

entered

she

tliem. §

She was

973

The cap-

r^g

still

in

34;°,

the current keeping her back just

After so great a

fast as slie could fan east.

andac-

very clever master, doubting his

ledseshis enor.

sensible .

Leavinor

of his error.

her

loss,

'-'

tain sees

own judgment, became tlie

spell-bound calms

.

.

behind him, where he had undergone such in his log as follows

:

" I

now

trials,

he wrote

making

regret that, after

so fine a run to 5° north, I did not dash on,

and work

my way

Roque, as

I

to

windward

have experienced

to the

little

northward of

St.

or no westerly set since passing

the equator, while three or four days have been lost in

working

to the eastward,

between the latitude of

8° north, against a strong westerly set;"

have added, §

97i

""

"

with

little

I!!f,' aid.

in the

and

and he might

or no wind."

In three days after this he was clear of J'^'^'^ fi"^®

5°

St.

Roque.

^^ys before him, the Hazard had passed exactly

same

place,

and gained two days on the

Fish,

by

cutting straight across the doldrums, as the Sailing Directions advised

him

to do.

42

ROUTES.

The Wild Pigeon,

crossing the equator also

5

33°, chapter

in

—

-

liad passed along there ten days before, as did also the

Trade Wind twelve days the line to the west of

The

after. 34;°,

latter also crossed

and in four days

after

-j-he

had

-wiid

^'s'^""-"

cleared St. Roque.

But, notwithstanding this loss of three days Fish,

who

so re^-retted

somely retrieved J

it,'

it,

she found herself,

November, alongside of the

on the 2-ith of

Gilpin, her competitor.

parallel of 5° south,

were then both on the

by the

and who afterward so hand-

They

§

976

^''®,„ overhauls t)ie"Gilpin-"

the Gilpin

being thirty-seven miles to the eastward, and of course in

a better position, for the Fish had yet to take advantage of slants, and stand off shore to clear the land.

They had

not seen each other.

The to

be

showed the Gilpin now to be in the best and the subsequent events proved the charts

charts

position,

right,

for thence to

on the Pigeon two

days,

53° south the Gilpin gained

§

977

^^"^(1^"*^^ ci'^^'ts.

and the Pigeon on the Fish

one.

By

dashing through the Straits of Le Maire, the Fish

gained three days on the Gilpin

;

but here Fortune again

deserted the Picjeon, or rather the winds turned against for as she

appeared upon the parallel of Cape Horn,

and was about

to double round, a westerly gale struck

her

;

§

978

^^1'^''/°^''^^^^

"^^''''

her " in the teeth," and kept her at bay for ten days,

making

little

or no way, except alternately fighting in a

calm or buffeting with a

coming

up, "

hand over

gale,

fist,"

while her pursuers were

with

fine

winds and flowing

sheets.

They

finally

overtook her, bringing along with them

propitious gales,

when

all tliree

swept past the Cape, and

§

979

THE PHYSICAL GEOGRAPHY OF THE

426

CHAPTER crossed the parallel of

—

•

d.mbie

"

51° south on the other side of the

Horn," the Fish and the Pigeon one day each ahead

tlie

were doing 980

Prevaiiing winds.

of

GiJpm.

The Pigeon was now, according best position, the Gilpin next, and

§

SE.\.

From

to the charts, in the tlie

Fish last

;

but

all

well.

this parallel to the south-east trades of the Pa-

The

w^inds are from the north-west. q[^q the prcvailino; ^ '-'

position of the Fish, therefore, did not

seem as good as

the others, because she did not have the sea-room in case of an obstinate noith-west gale. §

981

But the winds favoured

On

her.

Positionof crossed the (member the three ships • the vessels on 30th ^[)g Y\sh. recognising the Picreon ';

December.

the

80th of De-

parallel of *

85° south,

the Pigeon saw only J a & o o to " clipper ship," for she could not conceive how the ship

in sight could possibly be the Flying Fish, as that vessel w^as not to leave

she did

:

New York

for

some three weeks

after

the Gilpin was only thirty or forty miles off at

the same time. §

982

Excite-

ment

of

the race,

was now wdng and wing, and had become With fair winds and an open sea, the comi^eexcitinij. i '^ titors had now a clear stretch to the equator of two The

race

i

thousand §

983

five

'

hundred miles before them.

The Flying Fish led the way, the Wild Pigeon pressing her hard, and both dropping the Gilpin quite rapidly, who wa-5 edrjing off to the

westward.

The two foremost reached the equator on the

1 8tii

January, the Fish leading just twenty-five miles in tude,

and crossing in

1 1 2"

* Twenty-five days after that tlie

1

7' ;*

of

lati-

the Pigeon forty miles

Trade Wind clipper came along, San Francisco.

112°, and Jiad a passage of sixteen days thence into

crosse

-u

•o

CO

.-t

1

w»

•*

c

1

«

^

c

— -—

fc:

J;

5

C^O 2

,

"

« *

*

M >

^

I

|lL •

.

1

«

?

_

5C

Jj

„

m

Ol

i



trades

of the

we

the northern hemisphere,

of

way J

of corollary, that the counter•/

'

are not so easily arrested in their

south

''

back in

course, or turned

does in the

it

theii'

as

circuits,

are those of

j'j^^on™'' "^"''^ .

active ">*^

i!i

^"""'

ern tl;an '" *''«

nnrtliern

moreover,

Consequently,

the north.

''

•^

we

should

not,

ii*"'"'-

spliei-e.

either in the trades or the counter-trades of the southern

many

hemisphere, look for as

calms as in those of the

northern systems. holding

Therefore,

logy

following

the

sider

to

this

corollary,

established

as

facts

we in

maj'

con-

:—

That the south-east trade- winds are stronger than the north-east

that

;

the

north-west

counter-trades of the south

—

passage-winds

are stronger

and

—

counter- trades of the north

that the atmospherical

the cir-

in the southern

than

in the northern hemisphere; and, to repeat,

since

culation

is

the wind

moves

southern tlian it

;

more regular and brisk

the

less liable

to interruption in their circuits than the south-west,

it is

§ lOO'J

meteoro-

in its circuits

it

consequently has

in the south

more briskly through the

does through the northern hemispliere, less

time to taiiy or dally by the

way

than in the north; hence the corollary just

But observations also, as well as mathematically drawn inferences, show that calms are much less preva-

stated.

lent in the southern hemisphere.

For

are ample; they are grouped together

tens of thousands,

and Rain

Chai'ts.

V)otIi

this observations

by thousands and

on the Pilot and the Stonu

These charts have not been completed

New

facts

oiogy.

THE PHYSICAL GEOGRAPHY OF THE

44:8

but as far as they Lave

CHAPTER for all parts of tlie ocean,

I_L

this corollary.

These premises being admitted,

1010

^njerence

j.^^^,^^ from^iie yiieceding

beer?

constructed, the facts they utter are in perfect agreement

with the terms of §

SEA.

^,j^

^^ns ladder,

we may

and argue

ascend another the atmo-

that, since

sphere moves more briskly and in more constant streams ^jjj.Q^^orli

racts.

ir>

ei'n

o'eneral its o

than

it

channels of circulation in the south-

does through them in the northern hemi-

sphere; and that, since

calms as often should

it Ije

in

not arrested in

it is

the former as

by

in the latter, neither

it is

turned back by the way, so as to blow in that in which the

gales from the direction opposite to

general circulation carries

The atmosphere, channels

courses

its

it.

in its

movements along

ma}^ be likened,

of circulation,

its

regular

that in

the

southern hemisphere to a fast railway train; that of the northern to a slow. is

The slow

train

may, when

up," run as fast as the fast train, but

to get through so quick

way,

stop,

;

run back, and

therefore, still

it

it is

may

"

steam

not obliged

dally

by

be through in time.

so the fast; it has not time to stop often or to

the

Not

run back

far; neither liave the counter-trades of the south

time to

blow backward; consequently, such being the conditions,

we a

should also expect to find in the extra-tropical south

2:ale

with

eastinor in it

much more seldom than

in the

exti-a-tropical north.

We

shall appeal to observations for the

this conjecture,

and claim

for

it,

also,

correctness of

as presently will

appear, the dignity of an established truth.

TRADE- WINDS OF THE SOUTHERN HEMISPHERE.

449

Observations, with Easting

CilAPTEK xx.

and with Westing i'l them, betu'een corresponding Parallels in North and South Atlantic, ccs shown by the Storm and Rain

nuniber of

Average

Number of

Gales

to the

1000

the

Average gales in

Charts.

North and South tlie

Number

of observations Gales in 1000, with easting ... " " westing... ^Number of observations Between 45° and 50° -j Gales in 1000, with easting ... " " V westing... < Number of observations Between 50° and 55° j Gales in ]000, with easting ... " " '• westing... ^

Between 40° and 45°

-•

^

North.

South.

17,27i 23 66 11,425 2i 106

8756

4816

5169 10 ^7

Ailiintic.

12

82 5548 1

61

24 144

Thus the Storm and Rain Charts show that between the parallels of 40° and 55° there were in the northern liemisphere 33,515 observations, and that for every

observations there were 24 gales vnih. easting, and

In the southern there were 19,473 ob-

with westing.

and

servations,

for every

gales with easting,

Those

1000

of these there were 5

and 80 with westing in them.

for the southern

hemisphere are only for that part

through which vessels pass on their

01 the ocean

1000 105

way

to

and

around Cape Horn. That part of this route which lies between 40° and 55° south, is under the lee of South

fro

America; and Patagonia, that

lies east

almost a rainless region; consequently, to find

of the Andes,

we might

is

expect

more unsteady winds and fewer rains in that part

of the ocean

where the observations

of the tables were

with well out to

for the southern part

made than we should expect

sea, as at

probably be

much

meet

the distance of two or three

thousand miles to the eastward of Patagonia. the contrast presented

to

So that

by the above statement would

greater did our observations extend

entirely across ths South, as they do across the North, Atlantic.

But, as

it is,

the contrast 29

is

very striking.

In

Srher^ of tion in the

i.emi^''"^'^'

THE PHYSICAL GEOGRAPHY OF THE

450 CHAPTER

some

aspects, the meteorological agents of the

spheres, especially those forces

1

RKA.

and the weather,

which control the winds

very much.

differ

two hemi-

wide as to suggest greater regularity

The difference is so and rapidity of cir-

culation on one side of the Equator than on the other.

Numher of Calms to the 1000 Observations, between the Parallels of 30° and 55°, in the North and South Atlantic, and between the Parallels of 30° and 60° in the North and South

Average

Averaiie ^

oai'mr'

Pacific Oceans, as

shown by

the Pilot Charts.

ATLANTIC.

BETWESN THE PARALLELS OF 30"^

and 33°, No. of observations ... Calms to tlie 1000 do. 35° and 40°, No. of observations Calms to the 1000 da 40° and 55°, No. of observations Calms to the 1000 do. 45° and 50°, No. of obseiTations Calms to the 1000 do. 50° and 55°, No. of observations Calms to the 1000 do. 55° and 60°, No. of observations Calms to the 1000 do.

.

Average calms

Periods

to the

1

North.

South.

12,935 46 22,136 37 16,363

40

15,842 26 23,439 24 8,203 27 4,183 25 3,660 16

22,730 34 13,939 31 12,400 53 15,897 35 32,804 32 15,470 43

44,836 35 66,275 23 31,889 23 4,940 21 9,728 17 f 9,111 21

63,050

55.327

113,240

166,829

41

24

39

25

45

000

lo.

1

South.

8,097 38 3,519

Total No. of observations

PACIFIC.

North.

...

Each one of these observations embraces a period of

of the

foregoing observations.

eight hours; the grand total,

if

arranged consecutively,

with the observations drawn cut, each to occupy period separately, would be equal to

373

exhibit several curious and suggestive facts

its

They

years.

concerning

the difference of the atmospherical stability in the

two

hemispheres. §

1011

Causes of the ditfer-

ence of force In

the winds.

If

we would

discover the seat of those forces which

produce this difference in the dynamical status of the two great aerial oceans that envelop our planet, search for

them

in the

we

should

unequal distribution of land and

TEADE-WINDS OF THE SOUTHERN HEMISPHERE. water over

interrupted in their

wooded

chapter

by the continental masses, with snowy mantles in winter, their summer, and their mountain ranges

its circuits

In the other there

is

but

little

land and

the polar side of 40° south especially,

On

is

L

plains, their

sandy deserts in always.

In one the wind

two hemispheres.

tlie

451

if

we

less

snow.

except the

small remnant of this continent that protrudes beyond that parallel in the direction of Cape Horn, there

an

All

island.

There the

is sea.

air is

is

scarcely

never diy;

it is

always in contact with a vapour-giving surface; consequently, the winds there are loaded with moisture, which,

with every change of temperature,

is

either increased

by

further evaporation or diminished by temporary condensa-

The projjelling power of the winds in the southern resides chiefly in the latent heat of ^Ae

tion.

hemisphere

vapour which they suck up from 7

,7

-7

/•

/^

the engirdling sea

on

the soutii-

The Storm and Rain Charts show that within the trade-wind regions of both hemispheres the calm and rain curves are symmetrical the

symmetry

is

also, especially in

gale

and rain

Lieutenant

;

onhT^^'^'

winds of

•

polar side oj Uapricorn.

the

Reason of er propeii-

''

^j;;J;f

that in the extra-tropical regions

between the calm and fog curves; and the southern hemisphere, between the

curves.

Van Gogh,

of the

Dutch navy,

in

an

in- connection be-

terestmg paper on the connection between storms near

Good Hope and the temperature of the sea,^ It is presents a storm and rain chart for that region. founded on 17,810 observations, made by oOO ships, upon wind and weather, between 14° and 32° east and 33° and 37° south.

the Cape of

De Stormen nabij de Kaap de Goede Hoop Temperateur der Zee. '

in

verband beschouwd met de

twecn the temof tiie sea.

;

452

THE PHYSICAL GEOGRAPHY OF THE

By

CHAPTER

that chart the gale and rain curves are so s}Tn-

phenomena of

metrical that the

1

SEA.

extra-tropical

cause and

rains

TJie general storm

effect.

and

present themselves

seas

gales in the

suggestively as

and rain charts of

the Atlantic Ocean, prepared at the National Observatory,

hold out the same idea. explain this § 1012 Cause of

We •

ftict.

ascribe the trade-winds to the latent heat f.

f.

,

Let us examine, expand, and

Set ircc

,

i

i

thecounJincUof"

the equatorial calm -belt.

ernhemu

^^^^

sphere,

c

•

But

oi

which blow with

as

much

which

m

aqueous vapour

what

to

shall

we

ascribe

hemi-

the southern

particularly of

countcr-trades,

sphere,

i

irom the condensation

IS

regularity toward the

Pole as the north-east trades of the Atlantic do toward the Equator

Shall

?

we

say that those winds are drawn

toward the South Pole by

expand and ascend

which causes them to

heat,

in tlie Antarctic regions

somewhat paradoxical

It sounds

?

winds

to say that heat causes the

to blow toward the Poles as well as toward the Equator but, after a little explanation,

few

may

disappear.

It

Averajre

amount

of a

is

facts

by ....

held as an established fact

of

precipita-

and the passing in review

and circumstances, perhaps the paradox

the average

amount

oi

meteorologists that

precipitation

is

m •

i

greater

ii

the

northern than in the southern hemisphere; but

this,

imagine, applies rather to the land than the

On the

polar side of 40",

it

is

then,

gauges to

ments the

and on rare sea.

We

amount of

land of the two hemispheres; and I

It

is

only

now

that ships carry rain-

occasions,

can determine by quantitive measure-

difference in

determination,

I

mostly water in the southern,

mostly land in the northern hemisphere.

and

sea.

imagine,

that

precipitation on

it is tlie

has given

tlie

result of this rise

to

the

—

;

;

TRADE- WINDS OF THE SOUTHERX HEMISPHERE. genei-al

than

remark that the

it

is

rain-fall is greater for the

there

" times"

the

of precipitation,

report

whether

be in the form of rain,

a large corps of observers, rain

omitted in the log; so that in

do not show as "

hail, or

snow,

we may

Still,

in all parts of the sea

called

such

probability the charts

all

rain as there are

This omission, how-

sea.

one hemisphere as in the

ever, is as likely to occur in

other.

is

sometimes, no doubt,

is

many "times" with

times" actually with rain at

Our which,

Among

the charts, and in this discussion, rain.

1

sea

determinations are mostly numerical.

the

it

quantity at

for

observers

by

northern cuAPTta

But we have

southern hemisphere.

for the

few hyetographic measurements

453

assume that

safely

it

rains oftener

than our observations or the rain

charts that are founded on

them

indicate.

With the view of comparing the rains at sea between § 1013 the parallels of 55° and 60°, both in the North and South S'^T"" Atlantic, we have taken from the charts the following H'"^ '*'

: figures o

South

— Observations, 8110

gales,

;

1228

North—

„ 526; „ Gales to the 1000 observations Eains „ „

That

is,

10

for every

hemisphere 9

fall

„

64.

N. 256. N. 121.

why

more copiously at

4.7.

In which

on the average during a

Observations do not

to be a philosophical reason

oftener but

S. 131

in the northern

hemisphere does most water rain at sea?

rains, 1105.

there are in the southern

gales,

and

rains,

S.

;

135; 146 ;

it

tell;

but there seems

should rain not only

sea, especially in

the extra-

tropical regions, in the southern hemisphere, than in those

of the northern.

example, the land

On is

the polar side of 40° north, for

stretched out in continental masses,

Reason

™°'^ 7ai'n

jjj'°"q

t,°an\^,'" *j'^ j;;;'^:'; ^^''"^'^^

4 cHAriTR XX.

of

upon the

down

thirsty

t*°e"enthe "

ft^^d

SEA.

bosom of which, when the

load of moisture, only a portion of

its

taken up again; the rest

dew-

spheres"

THE PHYSICAL GEOGRAPHY OF THE

-t

On

the Springs.

is

drops

air

can be

it

absorbed by the earth to

the polar side of 40° south

we have

^ Water instead of a land surface, and as fast as precipitation takes place there, the ocean replenishes the air with

moisture again.

It

may, consequently, be assumed that a

high dew-point, at

least

one as high as the ocean can

maintain in contact with winds blowing over going from warmer to cooler latitudes

all

the time,

it is

and the

on the polar side of 40° south, whereas on the polar side of 40° north a low dew-point prevails. The rivers to the north of 40° could not, if normal condition of

they were to

make up

the

this

average difference of dew-point between

two hemispheres.

polar sidc of 40° south suggests that

andstoi-m-of curves,

converted into steam, supply vapour enough

The Symmetry of the rain and storm curves on the

Inference

symmetry

all

tlie air

this

it is

the condensation

vapour which, with the liberation of

heat, gives such activity

and regularity to the

its

latent

circulation

of the atmosphere in the other hemisphere.

1014

On

the polar side of 40° south, near Cape Horn, the

gauge of Captains King and Fitzroy showed a

rain-fall of

153.75 inches in 41 days.

There

is

no other place except Clierraponjie where the

precipitation approaches this in amount.

CheiTaponjie

is

a mountain station in India, 4500 feet high, which, in latitude 25° north, acts as a condenser for the monsoons fresh

from the

sea.

But on

45° in the northern hemisphere

American shores

of the

bility that there should

North

polar side of latitude

tlie it

is,

Pacific,

except along the a physical impossi-

be a region of such precipitation

— 455

TRADE-WINDS OF THE SOUTHERN HEMISPHERE. as

King and Fitzroy found on the western

Patagonia

—

ofcuArTEP,

slopes

a physical impossibility, because the peculiar

'

'

.

.

combination of conditions required to produce a Pata-

gonian

rain-fall

is

wanting on the polar

side

45°

of

north.

There

not

is

the North Atlantic water surface

in

causes

why more

enough

to afford vapour for such

an amount of precipita-

rain faiis in the

In the North Pacific the water surface

tion.

may

be

broad and ample enough to afford the vapour, but in neither

of these two northern

sheets

south than nortiu

of water are the

winds continuous enough from the westward to bring in the requisite quantities of vapour from the over,

More-

sea.

if the westerly winds of the extra-tropical north

were as steady and as strong as are those of the south, there

is

lacking in the north

that continental relief

mountain ranges rising abruptly out of the rated from to bring

it

only by lowlands

down

—

sea,

or sepa-

that seems to be necessary

the rain in such floods.

Colonel S3^kes^ quotes the rain-fall of Cherraponjie at Compan-

214 days from April to October, the season of the south-west monsoons. Computing the Cape Horn rains according to the ratio given by King 605.25 inches

for the

,

and Fitzroy

for their

tween the rain

fall a.t

chenaand

in Pa-

41 days of observation, we should

have a rain -fall in Patagonia of 825 inches in 214 days,

amount

or a yearly

Horn

of 1368.7 inches.

rains nor the rains

anywhere at sea on the polar

side of 45° south are periodical.

more copious perhaps abundant at

Now,

at

Neither the Cape

They

are continuous;

some seasons than at

others,

but

all.

considerinof the extent of water-surface on the

»

" Report

of the British Association for 1852," p. 256.

§

1015

THE PHYSICAL GEOGRAPHY OF THE

456 ctrAPTER ^^" ,

polar side of

why,

reason

tlie

SEA,

south-east trade-wind belt,

on these

see

no

engirdling air of

the

parallels,

we

that great watery zone of the south shoiild not, entu'ely

around the earth, be

was that which dropped

as

gonian

tainsoii le

upon the Pata-

had not been

there,

the condensa-

and the consequent precipitation would probably not

tion

ram-

^qq^ ^g gTeat, bccause the conditions at sea are

j^.^^,^

^

this flood

hills.

If those mountains

Effect of

heavily charged with vapour

as

less

apt to produce rain; but the quantity of vapour in the air

would have been none the

which vapour was

less,

borne in the channels of circulation toward the

beins:

Antarctic regions for condensation and the liberation of latent

its

we make,

heat; and

show, no \dolent supposition

we

as

shall proceed to

in attempting to explain

if,

this activity of circulation south of the Equator,

we

sup-

pose a cloud region, a combination of conditions in the Antarctic Circle peculiarly favourable to hea\y and almost incessant precipitation. Effect of

ti^'on"' '^

"'""

But before describing inquire

to

aside

how

conditions,

these

precipitation

far

may

posed cloud region of the south

and regularity

force

to the

let

in

assist

us turn

the

sup-

in giving

winds of the southern hemi-

sphere, §

lOlG

If

we

take a measure, as a cubic

and apply heat

to

it

by means

ties

may

of ice at zero,

of a steady flame that

will give off heat at a uniform rate,

that just enough heat

foot,

and in such quanti-

be imparted to the

we

raise its temperature 1° a miiuite,

shall find that at

the end of 32 minutes the ice will be at 32°. will

now

at 32° for

begin to melt, but

it

140 minutes, when

and all

its

ice to

The

ice

water yviU remain

the ice will have become

TRADE- WINDS OF THE SOUTHERN HEMISPHERE. \^'ater

This 140" of heat, which

at 32°.^

temperature of 140 cubic feet of

raise the

from any point below

32°, has

is

enough to

ice

one degree

become

chaptes L

been rendered latent in the

and

Freeze this water again,

process of liquefaction. this latent heat will

457

sensible heat; for heat

no

more than ponderable matter cannot be annihilated.

But into

after the cubic foot of ice has

if,

water at

32°,

we

been converted

continue the uniform supply of

heat as before, and at the same rate, the water

ture of 2 it wi]l

1

2°

—

will, at

180 minutes more, reach the tempera-

the expiration of

the boiling-point

;

and at

this

temperature

remain for 1030 minutes, notwithstanding the con-

At the

tinuous supply of heat during the interval.

1030 minutes

expiration of this

of boiling heat, the last

drop of water will have been converted into steam

;

but

the temperature of the steam will be that only of the boiling water

thus, in the evaporation of every

:

of water, heat enough cess

to

raise

is

rendered latent during the pro-

the temperature

one degree.

If

this

measure

of

1030 such measures

vapour be now condensed,

latent heat will be set free,

and become

sensible

tins

heat

again.

Hence we perceive that every rain-drop that the sky had in

enough to rain-drops.

come down

its

raise

But

falls

from

process of condensation evolved heat

one degree the temperature of 1030 if,

instead of the liquid state, as rain,

of

evolved by every rain piecipita-

it whether

in the solid state, as hail or snow, then the H^^^^

heat of fluidity, amounting to enough to raise the temperature

iient

140

additional

drops one

degree,

set free.

'

See Espy's "Philosophy of Storms."

is

also

458 CHAPTER

THE PHYSICAL GEOGRAPHY OF THE

SEA.

AVe have in this fact a clue to the violent wind which nsually accompanies hail-storms.

In the hail-storm, con-

the vio-

gelation takes place immediately after condensation, and

which"

so quickly, that the heat evolved during the

accom-

cesses

may

sequently, the upper air has

haii-*^

worms,

two pro-

be considered as of one evolution.

Con-

temperature raised

its

much

higher than could be done by the condensing only.

But

this is

digi-essive

therefore let us take

;

broken thread, and suppose, merely

up the

for illustration, such

a rain-fall as King and Fitzroy encountered in Patagonia to have taken place under the supposed cloud region of

the Antarctic Circle, and to have been hail or snow, instead of rain

among

the

then the total amount of caloric set free

;

clouds,

41

in those

days of such a

flood,

w^ould be enough to raise from freezing to boiling

times

much water

as

as

Antarctic precipitation come

But

fell.

down

if

the

6^

supposed

in the shape of rain,

then the heat set free would be sufficient only to raise

from freezing to boiling about 5| as much water as the flood brought down. §

We

1017

Amount

of

n

i_

have perhaps a better idea of the amount

shall .i

,

titbe

,

heat set

01 hcat that would

condensa-

and cougclation

co°n"ge"a-

vapour as

vapour.

"^'6

'^'^^y

in

make

illustration

tlie

m •

free,

-i

the condensation

the Antarctic regions of as mucli

took to

it

r

set

the Patagonian

by supposing

rain-fixll, if

this rain-fall of

153.75 inches to extend over an area of 1000 square miles, and that it fell as snow or hail. The latent heat set free

among

have been

sufficient

boiling point in area

the clouds during these 41

all

and 884

cold of the Poles,

to

2-aise

from

by

facilitating

daj-s

would

freezing to the

1000 square miles "We now see how the precipitation, is made to

the water in a lake feet in depth.

tlie

TRADE-^\^NDS OF THE SOUTHERN HEMISPHERE.

and develop

react

heat,

to

expand the

459

and give

air

chapter

force to the winds.

__1

Thus we obtain another point of view from which

we may contemplate

in

new

a

the

aspect

1018

§

icebergs

which the antarctic region sends forth in such masses and numbers.

They

are a part of the meteorological machinery of

The

our planet.

offices

most important, and

oh,

which they perform

how

exquisite

as such are

While they are

!

in the process of congelation, the heat of fluidity free,

which, whether

it

is

officas

by

ice-

^'^''

set

be liberated by the freezing of

water at the surface of the earth, or of the rain-drop in the sky, helps in either case to give activity and energy to tlie southern system of circulation,

expanding the

by warming and

air at its place of ascent.

Thus the water, which, by parting with has expended

liquefaction,

its

giving dynamical force to the

steam of the engine

become

It

inert.

is,

;

it

its

heat of

meteorological energy in air, is like

has

exerted

the exhausted

power, and

its

therefore, to be got out of the

way.

In the grand meteorological engine which drives the

wind through and

plant,

icebergs,

climes,

his circuits,

this

and tempers

waste water

it

and borne away by the currents

where the latent heat of

to beast, bird,

collected into antarctic

is

to

more genial

fluidity wliich they dis-

pense to the air in the frigid zone

is

restored,

and where

they are again resolved into water, which, approaching the torrid zone in

cooling streams, again joins in the

work, and helps to cool the air of the trade-winds, to mitigate climate,

and moderate the

gale.

For

if

the

water of southern seas were warmer, evaporation would be greater

j

then the south-east trade-winds would de-

use of

ice-

conveying north to

460

THE PHYSICAL GEOGEAPHY OF THE vapour more

CHAPTER liver '

abundantly to the equatorial calm

make

This would

belts.

SEA.

more

precipitation there

and the additional quantity of heat

set free

copious,

would give Thus

additional velocity to the in-rushing trade-winds. as has already

it is,

been

stated, that, parallel for parallel,

trans-equatorial seas are cooler than cis-equatorial

employed

that icebergs are

is

thus

;

push forward the

to

Effect of

it

on winds,

winds in the polar regions, to hold them back in the equato]-ial

and thus

;

machinery of the " coupled

is

it

we

air,

that,

in contemplating the

how

perceive

icebergs

are

and made to perform the work of a

on,"

regulator, with adjustments the

most

beautiful,

and com-

pensations the most exquisite, in the grand machinery of

the atmosphere. §

With

1019

cai force

wliicli

winds de-

01^6

vapoiir.™

this illustration concerning the

dynamical force

the winds derive from the vapour taken up in

climatc and transported to

"^^^d to sketcli

pro-

thosc physical features, which, being found

in the antarctic circle,

and constant

we may

another,

would be most favourable

precipitation, and,

heavy

to

consequently, to the de-

velopment of a system of aerial circulation peculiarly active, vigorous,

and regular

for the

aqueous hemisphere, as the

may

southern, in contrast with the northern one, ter-trade

the south-

called.

Thcsc vapour-beariug winds, which brought the rains

ThecounWindsor

be

to

•

-r*

Patagonia ^

•

>

1

are

—

t

I

•

wish

•

to

keep p

this

c

reader

vapour-

sphere.

wind's!^

grand system of

-i

aerial

circulation

;

and as

m '

fact

^

mind the counter-trades oi the soutliern As such the}^ have to perform their round

ernhdiiii-

s

—

i\

in

^

the

ihemi-

in the

every

system of circulation there must be some point or place

and commences to must be a place somewhere on

at which motion ceases to be direct,

be retrograde, so

tliere

the surface of our planet where these winds cease to go

TRADE-WINDS OF THE SOUTHERN HEMISPHERE.

and commence

forward, stop,

and

that i^lace

which, could

circle,

-J

'

band or disk within the polar

to be a

it

;

been determined,

locality has not

i-

suppose

I

their return to the north

chapter

all prohahility, tvithin the antarctic

Its precise

reqions. u

but

in

is,

461

ffl S;"rP''"s place of

"'^ "''^'^*

be explored, would be found, like

it

the equatorial calm belts, a place of light airs and calms, of ascending columns of air, a region of clouds

and of

constant precipitation. But, be that as

bearing winds

—

may, the

it

and flow

place has to ascend

grows

it

With

that which

for

In ascending

below.

cool,

which these vapour-

vapour-bearing, because they blow over

such an immense tract of ocean

make room

air

—pour

off as

into this stopping-

an upper current, to

continually flowing

is

expands and grows

it

condensation of

in

cool, and, as

vapour commences.

its

this vast quantities of latent heat,

which converted

the water out at sea into vapour for these winds, are set free in the

upper

There

air.

reacts

it

ascending columns, causing them

and so to

rise

by warming the

further to expand,

still

higher and higher.

This reasoning

suggested not only by the

is

fticts §

and circumstances already stated as well known, but derives

additional

plausibility

for

correctness

by

1020

it

the

low barometer of these regions. In the equatorial calm belts the mean barometric presabout 0.2 inch

sure

is

and

this

dnnmution

perpetual

influx

less

oi

of the

produce the trade-winds. barometric pressure^ 1

vol.

"Maur/e ii.

p. 450.

is

than

it is

pressure air

is

in the trade-winds,

tiicpres-

enough to create a

caim belts

from either Off

0.75 inch

Difference

side,

and

to

Cape Horn the mean less

than in the trade-

Sailing Directions," 6th ed., 1854, p. 692; ditto, 8th ed., 1859,

"** l^^^^^_ ''^'"'^**

462 CHAPTEE

THE PHYSICAL GEOGRAPHY OF THE

wind

This

regions.

is

According to

south.

for the

the

made along

observations

SEA.

parallel say of 57°

mean

of 24)72

—

8"

barometric

that part only of the route to

Australia which lies between the meridians of the Cape

Good Hope and Melbourne, the mean barometric presshown by Lieutenant Van Gogh, of the Dutch navy, to be 0.83 of

sure on the polar side of 42° south has been

inch less than sure

The mean

in the trade-winds.

it is

in this part of the South Indian Ocean

winds with easting in them, 29.8 inches;

winds with westing, 29.6

inches.

pres-

is,

under

ditto,

under

This gives a supposed

sure in

mean pressure in the polar calms of 29.7 inches. To what, if not to the effects of the condensation of vapour bomc by those surcharged winds, and to the immense precipitation in the Austral regions, shall we

latitudes,

ascribc this diminution of the atmospherical pressure in

Diminution of at-

mospiieii-

hio;h

south latitudes

?

It is not so in hisjh north lati-

tudes, except about the Aleutian Islands of the Pacific,

where the sea to windward precipitation

is

also

wide,

frequent, but not so heavy.

is

and where

The steady

flow of "brave" winds toward the south would seem to call for

a combination of physical conditions about their

stopping-place exceedingly favourable to rapid and heavy

and constant

and on the

what

precipitation.

those conditions are.

to perform,

which the

The

rain-fall at Cherraponjie,

slopes of the Patagonian Andes, reminds us

in the

There mountain masses seem

chambers of the uj)per

jet of cold

water does

in the condenser of the engine.

for the

air,

The presence of

not water, about this south polar stopping-place fore,

suggested

mountains are

;

the

office

exhausted steam

is,

land,

there-

for the sea is not so favourable as the

for

aqueous condensation.

'

463

TRADE-WINDS OF THE SOUTHERN HE]MISPHIRE.

By

the

terms

in

which

our proposition has been

465

air is the chief

to the

move

winds of ^^^^ their

throutrh o

channels of circulation, their high speed, great regularity,

And

and consistency of volume. •^

this insight into the °

_

^

we

w^orkings of the wonderful machinery of sea and air

is

research,

and

upon

fro

,

source of "le motive "=« ^'"^^

ofthe south-

inter- tropical seas.

the picture which, after no

little

labour,

much

§

1023

and some thought, the winds have enabled us

draw of

to

^j^

'^'^"^^

comparing together the relative speed of

obtain from

vessels as they sail to

Such

ciiapteu XX.

certain unexplored portions of our planet.

As we have drawn

the picture,

so,

from the workings of

the meteorological machinery of the southern hemisphere,

we judge

it

duced

meteorological in

is

to be.

character,

its

The evidence which has been

we admit

the antarctic regions

be plausible at

—

least.

its

but

;

it

intro-

nature, circumstantial in

shows the idea of land in

—

much land, and high land to Not only so it suggests that a

of

:

group of active volcanoes there w^ould be by no means inconsistent with

the meteorological

phenomena which

we have been investigating. True, volcanoes in a place may not be a meteorological necessity. cannot say that they are

;

such

AVe

yet the force and regularity of

the winds remind us that their presence there would not be inconsistent with we.

may

known

laws.

as well imagine the Antarctic Circle to encompass

land as to encompass water. little

more of

its

We know

ocularly but

topographical features than

those of one of the planets

we

According to these laws,

surely may, without

;

we do

of

but, if they be continental,

any unwarrantable

stretch of the

imagination, relieve the face of naiiu'e there with snow30

Evidence istence of

Ji^ vo'ca-

anurcuc* •'^sions.

THE PHYSICAL GEOGRAPHY OF THE

466

CHAPTER cia^j mountains,

and

SEA.

diversify the landscape with flaming

volcanoes.

None

are

features

of these

with

inconsistent

the

phenomena displayed by the winds. Let us apply to other departments of physics, and seek testimony from

None

other sources of information.

of the evidence to

be gathered there will appear contradictory,

it is

rather in

Southern explorers, as far as they have

Testimony

Corroboration.

piorers.

])enetrated within the Antarctic Circle, tell us of high

lands and mountains of ice of §

and Ross, who went furthest in the distance,

about twicc as large as Eui'ope.

area'ofthe IS

south pole.

;

saw volcanoes bm'ning

The unexplored area around

1024

ttie lines-

all,

South

the

7000

is

This untra veiled region

circular in shape, the circumference of

j^^g^^,g less than

Pole

miles.

Its

which does not have

edges

been

penetrated here and there, and land, wherever seen, has

been high and rugged. Navigators on the voyage from the Cape of Good Hope to Melbourne,

and from Melbourne

to

Cape Horn, scarcely

ever venture, except while passing Cape Horn, to go on the polar side of 55° south. icehergs

thcm.

Tlicsc

may

in tlie

"^

The

fear of icebergs deters

or

be seen there drifting up towards the

^

Bouthein

Equator

in large

numbers and large masses

the year

all

seas. .

round.

I

have encountered them myself as high up as

the parallel of 37° south.

The

belt of ocean that encircles this globe

side of 55° south

found in

all

is

parts of

never free from icebergs. it

the year round.

on the polar

They are of them The thick.

Many

are miles in extent, and hundi-eds of feet

area on the polar side of the 55 th parallel

of south

latitude comprehends a space of 17, 784', 600 square miles.

The nursery

for the bergs, to

fill

such a

field,

must be an

L

4G7

TRADE- WINDS OF THE SOUTHERN HEMISPHERE.

immense one

such a nursery cannot be on the

;

sea, for chapter

icebergs require to be listened firmly to the shore until

they attain

full

They,

size.

way, are loud with evidence

There

is

in their

cliffs

mute

in favour of antarctic shore

may

of deep bays where they

lines of great extent,

formed, and of lofty

therefore,

—

be

whence they may be launched.

another physical circumstance which obtains

Probabu

generally with regard to the distribution of land and

istence of

water over the surface of the earth, and which, as

ticcontu

it

goes,

far as

seems to ^favour the hypothesis of much land

about the South Pole

and that circumstance

;

is

this

:

It

seems to be a physical necessity that land should not be antipodal

to

land.

America and

Asia,

The

belief

is,

Except a small portion of South land

it

applies,

always opposite

is

we have

This law of distribution, so far

in favour of land in the opposite zone.

Finally, geographers are agreed that,

particular facts

water.

to

that on the polar side of 70° north

mostly water, not land. as

is

irrespective of the

and phenomena which we have been con-

sidering, the probabilities are in favour of

an antarctic

continent rather than of an antarctic ocean. "

There

is

now no

doubt,"

says Dr.

Jilek,

in his

"Lehrbuch der Oceanographie," "that around the South Pole there the polar

is

extended a great continent mainly within

circle, since,

although

we do

not

know

it in its

whole extent, yet the portions with which we

have

become acquainted, and the investigations made, furnish sufficient evidences

certainty.

to infer the existence of such with

This southern or antarctic continent advances

furthest northward in a peninsula south-south-east of the

southern end of America, reaching in Trinity Land almost to G2° south latitude.

Outwardly these lands exhibit a

Dr. jiiek's

oinmon on ti,e

s^b.

^'^'^'"

— 468

THE PHYSICAL GEOGRAPHY OF THE

CHAPTER naked, 1

SEA.

rocky, partly volcanic desert, with of

destitute

vegetation,

always

high

rocks

covered with ice and

snow, and so surrounded with ice that

it

is

difficult

or

impossible to examine the coasts very closely "

Discover-

reafthe"'^ south pole.

The

Dumont

principal discoveries of these coasts are (Wilkes), d'Urville,

and Ross (the younger), of

842 followed a

whom

the

100 miles between 72° and 79° south latitude, and 160° and 170° east longitude, to which he gave the name Victoria Land, and j^^|.gj, -j^

2

coast over

on which he discovered a volcano (Erebus) 10,200 feet and 77° south latitude, as

high, in 167° east longitude,

well as another extinct one (Terror)

10,200

and then discovered the magnetic South vatory, WasJdngton, April, »

" Text-book

by Dr. August

of

Oceanography

Ohser-

1859.

for the

Jilek, Yieniia, 1867.

feet high,

Pole."-^

Use of the Imperial Naval Academy,"

1

;

THE ATLANTIC TELEGRAPH.

CHAPTER THE ItsHistorj',

§

1025.— Attempt

to be

The

Atlantic Telegraph

after

having performed for

renewed, 1026.— Causes of Failure, 1027. real Question, 1029.

102S.— The

of Success,

communication only

XXI.

TELEGEAPH OF THE ATLANTIC.

SUB3VIAEINE

—The Probabilities

469

quietly

as

office

its

on

rests

a short time.

its

a

plateau, chapter

channel

The laying

was celebrated with a pomp and circumstance ^ •"

—

of

of

it T,,g^ji.'^

^e'eNew graph.

in

^^'^

York seldom, if ever, witnessed. Though short-lived it was a grand achievement. It demonstrated the possibility of uniting, by a telegraph across the Atlantic, the New World with the Old. Everything that contributed toward the accomplishment

of

achievement

this

possessed of that peculiar interest which attaches to

is

tlie

history of great events. It

is

in

some

sort a result arising

concerning the phj^sics of the it

may

sea,

from these researches

and a short account of

be given here without prejudice to the specialties

of this work.

On

the 1st of September, before an immense assembly

of people in the Crystal Palace of of this telegraphic enterprise

much beauty and and

in

eloquence,

behalf of the

New

rtsuistoiy.

York, the history

was given, in a speech of by David Dudley Field, for

Company

—he

being one of the

original projectors.

In

185

-i,

he and his associates had under consideration

a line from our

own

idea of extending

it

shores to Newfoundland, across the Atlantic

when

the

was suggested

First suit.

thepiaa

THE PHYSICAL GEOGRAPHY OF THE

470

SEA.

CHAPTER

but before they decided upon anything they wrote, said

^f!l

the orator, " to Lieutenant Maury, to inquire about the

Jector'stsk

^nt^lu'd. ry-sopin-

fessor

favour-

j^,

cable,

and consulted Pro-

Morse about the possibility of telegraphing through

On

Their answers were favourable.

-^^

wnich

ion, is

submerging a

practicability of

was decided

able.

It thus appears that this

embodied in the term

receiving '-'

them

"

ahead.' to 'go '^

new department

" Physical

of science,

Geography of the Sea,"

has already contributed to the advancement of one of the grandest and most interesting practical problems which this

age of mind and intelligence has been called on to

demonstrate. steamers to?ay"the "^^^^'

lu the

summer

of 1857, the United States steamer

"Niagara" and H. assigned

by

B.

M. steamer "Agamemnon" were

their respective

governments to the duty of re-

and laying the Submarine Atlantic Cable.

ceiving on board

Other vessels were sent with them as

The plan was,

tenders.

for

pilots, consorts,

Queenstown, Ireland, pay out her cable as far as reach, then pass the

when

it

.spliced,

would

and when that ship would After reaching deep

to Newfoundland.

it

it

end in mid-ocean to the "Agamemnon,"

woidd be

proceed with

and

the "Niagara" to begin at

water, the "Niagara" having paid out about 3 4 4 miles of First foil-

cable, it parted

August 11th, 1857.

This failure post-

uie.

poned further Second at. eir.pt.

trial till

the

summer

of

1

858.

In the Summer of 1858, the same two ^-^^

cable again on board,

ocean,

proceeded

ships,

having

together to mid-

where the two ends were joined, and they then

commenced

to "

pay and go," each toward her own land.

The "Niagara" had 1488 miles of "Afjamemnon" 1477. Total, 2965

cable on board, the miles.

After three unsuccessful attempts to lay the cable, and

— THE ATLANTIC TELEGRAPH. after the loss of

about 400 miles of

it,

47l

the fleet returned

It put to sea again for a last trial, July

to Ireland.

1

chapteis

7,

il

with about 1274 miles of cable on board each of the paying-out

vessels.

They met

in mid-ocean, joined cables,

and

set

out,

the "Niagara" for her terminus in Trinity Bay, and the

"Agamemnon"

for hers in Valentia

Harbour,

—

at 1 P.M.,

July 29th, and successfully landed each vessel her end of

success at last.

the cable on the

otli

after that

were passed through the

messages of congratulation liable

One week

of August.

First

me».

between the Queen of England and the President

of the United States.

The part which the Observatory has played in the history of submarine telegraphy, and of this line between the Old ])art

;

]>ortant

been,

it

it

and useful has

now

feiTiise.

But, whatever

out

commencement here

of

in

blossomed, and fruited, giving benefit charts of the winds secrets snatched

from

its

it

may have

that beautiful system of

1842,

has expanded and

among

its fruits for

and

man's

currents of the sea,

depths.

The

and

present, therefore,

seems to be a proper time for placing on record a state-

ment showing the connection this enterprise,

of the Observatory with

and the part borne

in

it

by each one who

has helped this institution to render good service in such

a

field.

In 1849 the labours of the Observatory in the hydrographical department of

its

duties appear to have attracted

the favourable consideration of Congress of that year a law

was

Ohser.

appears to have been an im-

is

research concerning the physics of the sea, which, having its

tiie

with the

part.

grown

nection of

a quiet and an humble

World and the New,

nevertheless,

the con-

;

for in

March

passed directing the secretary of

THE PHYSICAL GEOGRAPHY OF THE

472 CHAPTER the

" to detail three suitable vessels of the

navy

testing

new

by Lieutenant Maury

to°aid'tbe

^^

t'onsofthe Observa-

navy

vessels of the

in

made

in the course of his investigations

winds and currents of the ocean

f^j, g^jg]^

navy

routes and perfecting the discoveries

BeTbr^

^^^®

SEA.

;

and

to cause the

to co-operate in procuring materials

investigations, in so far as said co-operation

may

not be incompatible with the public interest."

Under

The

this

law the United States schooner "Taney,"

Bchooncr

"Taney"

Lieutenant

make

1849. '

a

J. C.

Slic

series

therefore,

was

Walsh commanding, was sent directed,

among

to sea in

other things, to

make

She was provided, of deep-sea soundings. with fourteen thousand fathoms of steel wire, and

a self-registering deep-sea sounding apparatus,

Mr. Baur, of

New

a plan designed in this fathoms of

made by

York, from drawings and according

line out,

She got a

ofl&ce.

when

it

cast with

to

5700

parted, losing the apparatus.

She then proved unseaworthy, was condemned, and sent back under Longing excited for further iu-

escort.

This reported sounding served to stimulate that longing

,. ,.,.., implaiitcd

which

IS

111

human

the

,.

,

mysteries and the wonders of the great deep this time

,,

breast touching the ;

for

up

to

no systematic attempt had ever been made to

fathom the deep

Sporadic casts of the lead had

sea.

been made here and there in

"

blue water," but though

the reported depths had been great, yet, as with that of the "Taney," there always remained a doubt as to whether

bottom had been reached or to this time

we were

not,

and at what depth.

Up

as ignorant as to the real depths of

the ocean, and the true character of that portion of the solid crust of our planet

are at this of Jupiter.

moment

which constitutes

its

bed, as

we

of the interior of one of the satellites

Using astronomical elements, the mean depth

;

THE ATLANTIC TELEGRAPH.

x

theory, about

My

bad been calculated

ocean

the

of

23

to be, according to chapter '^

miles.

excellent friend, the late

who was

Commodore \Yamngton,

then the chief of the Bureau of Ordnance and

Hydrography, of which the Observatory as

was

the

473

his wont, liberal

plan

deep-sea

of

now

soundings

navy regarded

he was

ready

to

required,

and the law it

a branch, took,

and enliejhtened views touching

secretary of the

such auspices,

is

afford

it

every

itself

was decided

was

The

proposed.

with a lively interest that

the law

enough.

Under

facility

liberal

to inaugurate a regular plan a

of deep-sea sounding for the American navy.

Accord-

repiiar

deep-sea '''^''

formulae were arranged, methods prescribed, and'^°""

ingly,

our men-of-war were furnished with the requisite twine, &;c.,

and commanded

to use every suitable

and convenient

opportunity while at sea to try the depths of

Each

waters.

vessel

was allowed a number

its

deep

of reels of

this twine,

accordincr to her cruisino; m-ound,

containing

ten

each reel

thousand fathoms, weighing about one

hundred pounds.

Under

this order,

Lieutenant William Rogers Taylor, a

the 1st of the "Albany," Captain Piatt, commenced a series of soundings in

and about the gulf of Mexico

;

Captain

Barron, of the "John Adams," ran a line across the Atlantic;

and Captain Walker, of the "Saratoga," got a

cast in the

South Atlantic.

1851

All these soundings required verification; and in

the "Dolphin," Lieutenant-commanding out,

S. P.

under the act of 1849, especially to

observations and experiments.

many casts,

failures,

After

Lee,

assist

many

was

trials,

she at last succeeded in getting

which, being reliable, enabled

me

fitted

me with and as good

to establish a

law

senes ot

com-

474

THE PHYSICAL GEOGRAPHY OF THE

CHAPTER of descent for the '.

plummet, and so prove the soundings

of other vessels.

"made

Lieutenant Lee, having thus

Successor

nant Lee.

SEA,

its

Bud," returned home, bringing with

the egg stand on

him the

best series

of deep-sea soundings that up to that time had ever been

made

;

and they have not been surpassed by any up to

this day.

The "Dolphin" was then placed under the command of H. Berryman, to continue this service.

Lieutenant 0.

With

Lee's plans

sea from

New

and experience

to guide him, he put to

York, October 1852, sounding as he went

as far as the meridian of 40° west,

taken by a

gale,

where he was over-

damaged, and forced into the Tagus

Here he remained

for

December 19 th, and then returned home by the southern route, sounding and lookrepairs.

ing for

With

Anoro-

map

con-

" vigias " as

till

he came.

Lce's soundings in the "Dolphin," together with

thosc already obtained from the regular cruisers in the

the bed of

navy, I was enabled, with the

AHantic

^lyc, to coustruct, in the

Ocean.

fall

of

assistance of Professor

185 2, an orographic map

^^ ^^^ ^^^j ^£ q^^ North Atlantic Ocean, and to give a profile

representing

between

this countiy

a

vertical

section

of

and Europe near the

its

bottom

parallel of 39°

north.

The materials used

The matefor

Ihe^

jnap.

for this

map^ and

deep-sea soundings already mentioned as Taylor, Lee,

profile

were the

made by Walsh,

and Barron, together with others which had

been received from the "Congress," Commodore M'Keever the "Portsmouth," Captain Dornin

;

;

the "Cyane," Captain

Paine; the "St. Louis," Captain Ingraham; the "Plymouth,"

1

See Plates

XIV. aud XV., " Maury's

Sailing Directions," 5th edition.

1

475

THE ATLANTIC TELEGRAPH. Captain Kelly; the

"

Germantown," Captain Knight

"Susquehanna," Captain Inman

;

maps

the chapter

—

These were the

of the "Jamestown," Captain Downing. first

;

and Lieutenant Warley,

of the kind ever attempted for " blue water."

Their object was to show the depressions of the solid crust of our planet helorv, as geographers seek to repre-

sent

The

elevations above the sea-level.i

its

plateau"

there delineated on Plate XIV., very

is

the subsequent deep-sea soundings have shown

This attempt to

map

much

it

as

to be.

out the bottom of the deep sea was

regarded with exceedino: interest by the learned.

Hum-

and most

it opened the freshest boldt gave it high praise ° interesting field that remained to him for contemplation ;

.

in the

Up

domains of to

this time,

however, nothing sea.

and the sounding-line a

was broken

off

so that ball

.

.

when the

t'"^

sub-

jeet.

had ever been

The plummet was a canbit of small twine which

cannon-ball reached the bottom,

and twine remained behind

;

consequently,

every cast of the deep-sea plummet involved the a shot and of as

"i™teiest in

science.

brought up from the deep non-ball,

.

" telegraphic

much twine

as it

loss

of

took to reach the

was desirable to bring up soundings, not only that we might learn what the bottom and bed of the ocean were made of, but that we might know of a verity and have the proof that the bottom had been bottom.

It

reached.

Under these circumstances, the attention of Lieutenant J. M. Brooke, who was at the time stationed at the Observatory, was called to the subject, when he made, for bringing up specimens froiri the bottom, the beautiful and

contriv-

bringing

m^ensfrom "'"

of tbe

ocean.

'See p. 239, 240, 5th ed. "Maury's Sailing Directions," printed by C. Alexander, Washington, and published in February 1853.

;

THE PHYSICAL GEOGRAPHY OF THE

476

known

CHAPTER simple contrivance XXI.

apparatus.

When the

,

ordered to sea to Ob-

as " Brooke's deep-sea sounding

,)

,

^. The ..^ "DolP'"""

returned from the "Dolphin" i

Tacnis, which she °

did in March 1858, arrivinor " at Norfolk on the 7th of to sea again under Berry\^\^^\^ nionth, shc was ordered

tain speci-

_

_

uieus.

SEA.

man, to

assist still further " in perfecting the discoveries

made by Lieutenant Maury

might procure specimens of the bottom,

first

first

time that

time

was put on board any

it

was used was

it

midshipman on board that

Mitchell, then a

boat;

it

all

occupied

since Lee's time,

six

hours.

fathoms, and the rod came up,

The

1853, in

by

brig.

The depth was its

was

J. G.

This

was made from a

2000

arming loaded with

This promising young

precious trophies.

this

vessel.

at 1.20 P.M., July 7,

latitude 5 4° 17' north, longitude 20° 33' west,

sounding, as were

that

this apparatus

was put on board the "Dolphin;" and

of Brooke

the

And

and currents of the ocean."

tion of the winds I

in the course of his investiga-

officer

made

every deep-sea sounding that was made in the "Dolphin"

during that The

first

obtained,

save one only, and to him belongs the

cruise,

liouour of bringing

up the

first

specimen that was ever

obtained from the bottom of the deep sea.

during this

but the

cruise, several

first

Subsequently,

other specimens were obtained

was described by Mitchell

as " a fine chalky

clay."

The "Dolphin" returned

in

November 1853.

Her

soundings during these two cruises with Brooke's apparatus were

first

published in the sixth edition of " Sail-

ing Directions," March 1854.

The specimens from the

bottom were forwarded to the Observatory, and by sent to that charming Bailey, of

West

man

me

of science, the late Professor

Point, for examination under his micro-

—

;

477

THE ATLANTIC TELEGRAPH.

He examined

scope.

and found those specimens

tliem,

"

from the bottom of the great deep not to have tide of

sand or gravel mixed were when

'par-

forces at play

is

\

mensToiu

unworn and un-

l^eoceaa'

alive.

T-'nirmt

This discovery of the miscroscope at once suggested the idea that there

'.

but to be mites

ivith tliern,"

of sea-shells, perfect in form, and as triturated as they

a

cHArrER

T

Wf West

ll"

,.. ,1

W.M.W.

73?

mw.

.™

174 SOS

Xlf.W.

,n»=

..

5-Notih

...t:l

1 1

I )5Tasr.

H 0-

1

u5-E.

.

.

OULI^'

STllEAM

AND

DRIFT.

KX P

a

Thf place

_

I't'

I,

FINITE

A \AT

I CJ

5

..r

%

>v>^>'

.

San Ft'Uirtaro aJ'tjer the wre^k aJtojutoned Jan '>

the

//.

o _ Where rf/ir tvtw aM Computed (u»uU oV Drift

WiJfre the settivhint/ vtsufl

e .v.y.x

*

Thf^hot

JitreaJe.T

wus direeied

of Fio.

-J)ire£tum of Flow

and

PUn*, not tteady in ani/

to

Inok for

--tc'lS"'. '•.:•"

A O/'if'

dire*-tioit

P-

fi

\

' 1

^..'1

.y:i

'i;.,,

I

NEISOK t

SOJiS.

lOSBOX.XDrNBTJaGH i NIW

VOELK.

VI.

r

„

I

(

A

GEOLOGICAL AGENCY OF THE WItfDS

PIATE

F.xpl.'uiafinu.

The

.ih,t/'i i.»

.m/>f>os,-il

hi-

/v.t an

the shoilint) C, vhrn' it

ttitit

.

/«'

7/1 -•

thr nil/i

up: Thr nands

(iiAvn

srvroRX.

VR.

U/.\.'>S

IXI)

NOITHS

PL.riK vin

rr^^^Fr^^^ S-^ .i

^^^R=7^

# ^*^^^ 5 5» '^

EXI'LASATIOX .-.'

"v>^.

.V,„lJ,

Saul Tra.l^^

.¥„„//. Jf.ul

Tvirffs

-^r^:

>-^ V^'

I'rrraiUntj WfiStwartU^/ J\'m/tg

v>A M ^-'"^Y\

^

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