The Works of Pier Luigi Nervi


323 21 9MB

English Pages 162 Year 1957

Report DMCA / Copyright

DOWNLOAD PDF FILE

Recommend Papers

The Works of Pier Luigi Nervi

  • 0 0 0
  • Like this paper and download? You can publish your own PDF file online for free in a few minutes! Sign Up
File loading please wait...
Citation preview

mmmivm/jMM/MMi!miMMiim/mmMMm}MmmM^Mmim

CHRISTOPHER

JOHN CHAMAliS

ARCHIIEa CITY PLANNER SOUTH LA SALLE STREET CHICAGO J, ILLINOIS )I

?o

June

'S*

The Works

of Pier Luigi Nervi

.

/

Digitized by the Internet Archive in

LYRASIS

2011 with funding from

IVIembers and Sloan Foundation

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

The Works of Pier Luigi Nervi

Preface by Pier Luigi Nervi



Introduction by Ernesto N. Rogers

Explanatory notes to illustrations by Jurgen Joedicke

Translation by Ernst Priefert

CHRISTOPHER JOHN CHAAAALES CITY PLANNER SOUTH LA SALLE STREET CHICAGO 3, ILLINOIS

ARCHITECT

11

3^

Frederick A. Praeger

New

York

joue i9»S

BOOKS THAT MATTER

Published

in the United States of America by Frederick A. Praeger, Inc., Publishers.

15

West 47th

Street,

in

1957

New

York 36, N. Y. All rights reserved by Verlag Gerd Hat/e

Ubrary of Congress Catalog Card Number: 57-9676 Printed in

Germany

Contents

Preface by Pier Luigi Nervi

vi

Introduction by -Ernesto N, Rogers

ix

Illustrations

Cinema "AugusteoH, Naples The Municipal Stadium of Florence Design Design Design Design Design

'

for for

hangar for a revolving house Prefabricated house for a circular

Storage tanks for crude

18 19

20 21

in steel

22 24 26

oil

A hangar Hangar Hangar

2

4

grand stand of a stadium in Rome, seating 100,000 a bridge across the Biedano Valley near Rome a circular hangar in reinforced concrete

for the

28

of pre-cast

concrete components

of prefabricated concrete components Sketch designs of Exhibition Pavilions for the World Fair at Rome Sketch design of a large hall in prefabricated reinforced concrete

34 36 44 units, clear

Design for a Station Hall of prefabricated components Reinforced Concrete Ship of 400 tons Storehouse in Rome Covered Swimming Pool of the Naval Academy of Leghorn Wharf Conte Trossi, San Michele di Pagana (Genoa) Sketch design of a hall with special shed construction for thermal insulation Design for a Station Hall in Palermo of prefabricated units of ;;

'

i

!

.iiiiiiiiiii

tilllliiiiiiM,,;:;'-,

^^^

~^«diii)li;!ii||

-r"

.''ilIBB

1

Elevation and section of pre-stressing

apparatus, 1

Shuttering

drum

concrete

of

2 Horizontal rubbertubes for building

up pressure 3 Connection between

warm water

pipes 4 Verticalhollowsectionsforthe

transmission of pressure 5 Pre-stressed core of

tlie

concrete

pipe 6 Outer skin I'/m incfies of fine aggre-

gate concrete with spiral reinforce-

ment 7

Lock

2 Sending of spiral reinforcement over a

wooden drum, 3 Detail of the pre-stressing apparatus.

The

horizontal rubber tubes for the

building up of pressure are visible.

the vertical hollow plates is

In

warm water

circulated to accelerate the setting

of the

cement,

4 Manufacture of pipes

in

the workshop.

5 Cross section through pipe, showing

method

J|/\

of

supporting.

6 Transportation of finished pipes. 7 Laying of pipes.

These pipes have a which they

projection on either side on

In this way bending moments caused by unequal loading are reduced toa minimum.

are supported.

8 Connection of two pipes. 1

Outer skin

2 Pre-stressed core

3 Mastic 4 Sheet metal 5

Cement mortar

Tobacco factory In

at

1949 a competition

Bologna - 1952 was held by the State Monopoly Administration

for the most economical design solution of a 5-storey factory measuring 700 :; 80 x 90 feet. Determined by technical as well as economical considerations is the construction of the two identical floor

slabs with an area of 260,000

sq.ft.

Nervi developed a special technique for this

job using shuttering boxes of :e.-Tij{^=s;^^

Section showing the different levels.

7

3

Plan at level 59.95 m. (196 feet) 1

Entrance for spectators

2

Entrance for athletes

3 Ascent to the main hall

LI IJJJJ"^'

m\

4

Showers and

5

Cloakrooms

WCs

(for

50 and for 2-6

people)

"

6 Training quarters

7-9

Rooms

for

massage, steam bath

and sauna 10

Changing room

11

Technical management and um-

for the choir

pires

12 Doctor

and

First

Aid

management

13 Central

room Practice room

14 Resting 15

for boxing, judo etc,

16 Training quarters

room for table tennis room for rowing 19 Practice room for gymnastics 20 Day room for 50 people 21 Practice room for fencing 17 Practice

18 Practice

EES

EIE^'jl^

22 Multi-purpose room 23 Running track 24 Kitchen with stores and servery 25 Restaurant 26

Gymnasium

27 External escape stairs

28 Stores 29 Practice field for hockey etc.

30 Hall 31

Box

for

gymnastics

offices

32 Ice rink 33 Rollerskatingrink 34 Parking space (at various levels)

9 Plan at level 63.20 m. (207

f(

H^:

6 inches)

...^^s^r

*T-^:

?

k»=^..

If-LLLLLLLLLLd

10 Plan at level 68.70 m. (225 feet 6 inches) 1

External escape stairs

2

Raised platform of practice hall

3

Access

to the

ramps

4 Gallery 5

Cloakrooms

6 Access to lavatories 7 Seating

accommodation room for 3,600

8 Standing

9 Cycling track 10 Running track 11

Access

to seating

12 Entrance for athletes 13 Administration

for 8.400

....

n

Section through east-west axis.

12 Gallery

belowthe seating,

13

Viewof the

interior of the

main

hall.

BB and CC through

14 Sections

pre-

cast units. 1

Pre-cast reinforced concrete

element 2

Duct openings

3

Window area

for the air-con-

ditioning

4 Prefabricated

pendent

beam

of the inde-

flat roof

concrete connection of the

5

In situ

6

Window area

7

In si'fu

pre-cast units

concrete

8 Acoustic treatment 9 Pre-cast roof units 10 Sheet aluminium for water-

proofing and thermal insulation

1?

15 Section through

AA

dome

with section

through concrete supports.

1

Mainductsof air-conditioning plant

2

Roof lights

3 Covering of sheet aluminium

5

The construction mentOM which

main

hall consists of

corrugated pre-cast units of «ferro-ce-

on inclined supports of reinforced concrete. At the junction

of

the

construction and pre-cast construction are the air-conditioning ducts through

in situ

which warmed units

of the

rest

air is circulated to

were planned

to

the duct openings

in

the units. The prefabricated

be similarto those of the great Exhibition Hall

are joined together by continuous bars

embedded

in

concrete.

In

in Turin.

The

units

contrast to the Turin

solution Nervi here had planned for a second roofing skin over the pre-cast units. In this

way

better thermal insulation

would have been obtained.

16 Placing of pre-cast units. 1

Tubularscaffolding

2 Centring forthe support of the units 3

tvletal rail for

4

A

placing the units

unit being placed in position

{maximum weight

2,650 lbs.)

17-19 Perspectives and plan of an external escape stair

ty

^^

The practice

hall for various activities adjoins

the north side of the large

Similar to the construction of the Congress Hall of the Nervi curves the roof to the line of compression effect

and

pendent

results in steel

flat roof of

economy

for the

I

Plan and section of structure.

22 Perspectiveof the practice hall.

domed

Building

in

hall.

Paris,

the beam, This gives a spacious It

necessitates, however, an inde-

pre-cast units to allov/ access to the roof.

20 View of the practice hal from the outside. 21

in

beams.

UNESCO

'- ..•jBBsagsggTissaagg^g.

siiia»«iaB 1

Map

of

2 Site plan.

neighbourhood.

1

Secretariat

2 Conference block 3 Executive

4 Foyer

UNESCO

Building

in

Paris - 1953/56

Architects: Marcel Breuer, Pier Luigi Nervi

The curved north side

of the

and Bernard

H. Zehrfuss

Y-shaped secretariat forms part

of the group of buildings around the Place Fontenoy. The south siJe opens towards a new square which is bordered by the projecting Conference Building. The outline of the main building forms an extremely clear-cut shape. Lifts, staircases and vertical services are in the core of this

Y-shaped block. The vestibule space diverges into corridors which lead to offices lifts and secondary stairs are at the ends of each wing.

on both sides. Further

The conference block

is

linked by a «clip» to the office building. This block contains the

architecturally interesting Conference

Room and

several session rooms.

committee

4 Photo ol model.

'S)

3 Plan of a typical floor. 1

Offices

2 Director Ger^eral 3 Vestibule 4

space

WCs

5 Stores

6 Gallery ot the foyer 7

Committee rooms

8 Cubicles for simultaneous interpretation

9

Room

for

Commissions' sessions

10 Press and public 11

Projection cfiamber

12 Accessgalleryforttielighting

13 Conference

tiall

The Secretariat

is

a reinforced concrete frame structure

in

wtiich

ttie

main supports are

inset from tlie face of the building.

The

condary beams. All services are

ducts above the central corridors. The beams taper

off

in

floors are carried by a series of

towards the outside where they carry the

5 Section through structure. 6 Plan of structure and ceiling.

brtse soleif of reinforced

main and

concrete.

se-

structure of ground floor.

ground

level in

supports

is

The upper structure

which the columns are raked

is

supported on a

rigid porta!

to give greater stability.

frame

The shape

at

of the

dictated by the geometric problem of transforming the elliptic section at the

base to the rectangular junction

v^ith

the ceiling. The plastic form thus evolved

is

the

characteristic element of a purely architectural treatment of reinforced concrete. 7

The supports

at

ground

floor level.

8 Sectional elevations (above) and tight

angles to the main fapade

plans (below) of one ground floor support: at

(left)

and parallel to

it

(right).

i

The ground centre

is

floor during construction.

the multiple

lift

shaft,

View

of the junction of the three wings, In the

10 staircase during construction.

11

Plan and section of stairs.

from a spine wall.

In

an unconventional manner the treads are

canti levered

IV

i;

-

i: I

AT

^

12

The canopies atthe entrances tothe Secretariat are of unusual design. The canopy of shown above still adheres to the conventional solution of a horizontal

the north side roof

on supports; but

designed

tor

I

II

III

it

columns.

Plan

Underside section E£ Section

IV Section

has an interesting pattern on the underside. The whole

rough concrete work leaving shuttering marks

are cast into the

BB CC

visible.

is

The down pipes

mos

13

The canopy

of the

south-west side shows an unprecedented solution,

metrically placed arch forms the support for a three-dimensional tilevering on both sides. I

II

III

Plan and section

The thickness

of

the slab

is 3'/i

ly

An asym-

curved slab can-

inches.

DD

Elevation

Section

AA

IV Vertical section

tB=3^

D-D

14 Plan of roof structure.

15

The

The Conference Building during

roof of the

which

is

Room an

Conference Building

erection.

is

a folded slab construction

stiffened by a central up-stand

extremely spacious solution

is

beam

in

reinforced concrete,

carried by six supports.

In

the Conference

achieved by raising the slab between the folds.

The roofing slab Is being utilised to full advantage by following the direction of the compression forces. The continuation of the folded slab structure around the gable walls provides the necessary lateral stiffeners for wind moments. There are few examples of modern architecture where such a convincing form has been achieved integrating architectural

and structural design.

16 Interiorof

Conference Room.

100

300 200

B

/vVW::

-

50

mto

17

^00

B

sAAAA>

The bending moment diagrams show the forces and the

direction of the stresses in

the structure. Above the Conference Room, as can be seen from the diagrams, considerable compressive stresses occur in the upper parts of the folded slabs.

here

is

raised to follow the line of compression, forces thus being

in

The slab

compression

throughout. 17 Bending

moment diagram.

18 Cross sections through the structure at 1

Zero

AA

and

B8

(see

moment

diagram).

line

2 Stressing zone 3 Tension zone 19 Deflection diagram of the structure under vertical loading, indicating compression

and tension zones. 1

Upper stressing zone

2 Central stressing zone 3 Lower stressing zone

20 Longitudinal section

120

21

+

22 The Conference Block during erection.

•'^^^\'^^\'^>»^*

.WC^~.i'^>,|^

24 Placing of folded slabs and laying of reinioiceftients.

23

A

centre support of the Conference Block

in tfie

course of erection.

25 The cladding of the folded slab construction.

26 The folded slab construction of the Conference Block during the finishing stages.

F

1

Longitudinal section showing method

6 Movable scaffolding for the casting

of construction, 1

of floor slabs

Shuttering about to be raised to

7 Prefabrication of girders for floor

its

position 11

10

2 Shuttering

!

position

in

Completed bay

of floor

3 Finished floor

C

B

9 Prefabricated girders erected

in

position

4 Prefabrication of girders for floor B

10

Movable scaffolding

11

Completed bay

5 Prefabricated girders erected in

for the casting

of floor slabs

position

of floor

C

2 The building (21iX) feet long) during erection.

Factory buildings for the Fiat

Works

The advantages

based on prefabricated reinforced concrete units are

of a construction

at Turin - 1955

is vary large, and when one can limit the number of These two conditions were present with this project to a high degree.

especially apparentvifhen the building different elements.

The

threa-story building has the unusual length of 2103 feet

and

a

width of 66

feet.

The

building had to be erected within fiva months. After allowing for time to install the site

equipment, only four months ware

left, This tima-limit was even improved on, as the was erected within 100 days. The construction is clearly explained through the diagram above. The shuttering for the ground floor slab consists of «ferro-cemento» (illustration 4). The shuttering rests on a travelling scaffold and can be lowered after striking and moved into the adjacent bay. There are two intermediate columns at basement level (Illustrations 3 and 6) but the

building

other two floors span across the complete width of the building. The ground floor

construction consists of pre-cast girders at 8

ft.

girders are constructed

in sifu

concrete while the upper floors are constructed of

2 in. centres with in

ifj

si/u

slabs (illustrations 7-10), The pre-cast

similarshuttering to the ground floor slab.

B

I

U.a.M

The shuttering for the ground floor slab mounted on movable scaffolding. 4 Section through ground floor slab showing the removable shuttering of "ferro3

cemento», 5 Section through the upper floor slab, showing the removable shuttering for the

construction of the 6

in silu

slab.

Diagram showing the placing

of the girders.

7

A

girder ready for casting. All shuttering

easy removal.

is

specially treated before each casting, for

3

Finished girder ready to be placed

in position.

The protruding bars are for the is so smooth as a

connection with the framing beam. The surface of the girder of the

f\r\e

in silu

result

aggregate concrete sfiuttering that any further treatment or rendering

unnecessary.

is

9 Hoisting a girder into

10 Underside of

first floor

girders,

The loads

differ

from

slab can carry a superimposed load of 200 !bs./sq.

100

lbs. /sq.ft.

and 50

lbs. /sq.ft. respectively.

floor to floor, ft.

The ground

floor

while the other floors carry

1

The model from the

east.

The theoretical investigations were helped by

tests

which

the «lstitutoSperimentaleModeliieStruttura» (Institute fortesting models and structures) conducted.

Office Building for Messrs. Pirelli in Milan - 1955/56 Designed by: Gio Ponti, Architect; Antonio Fornaroli, Engineer; Alberto Rossellr, Architect;

Giuseppe Valtolina, Engineer; Egidio dell'Orto, Engineer

Structural design: Arturo Danusso, Pier Luigi Nervi

The main problem which the erection of a tall slender structure poses is the provision of wind bracings, Two rectangular supports which branch out in the upper floors serve as cross bracings{see illustration 7 on page 131). The width of a supportin the basement is 6 feet 7 inches tapering to 12 inches at the top of the building.

The triangular end walls form lateral wind bracings to some extent but they are mainly for longitudinal stiffening.

A

curtain wall of 108,000 sq,

ft, is

across without intermediate supports,

rows

of pre-stressed reinforced

of 2 feet 6 inches.

attached to the structure. The floors span right i,

e.

79 feet. This unusual span

is

achieved by

concrete beams at 5 feet centres, which have a depth 128

1

2

Plans of structure at

1st, 15th,

3

and 30th

floors.lt is clearly visible

how

the area of the

on page 131), The triangular end walls hold the fire escape stairs, lifts, and the air-conditioning ducts. The internal corridors taper off towards the ends according to the diminishing amount of use; they are widest in the centre of the building where there is a group of six lifts on the north

load-bearing structure

The plan

side.

is

rational

in all

reduced

in

relation to height (see illustration 7

and functionally well thought

The subdivision

placed

is

of the

directions on a 3

rooms ft.

1

in.

is

extremely

x 3

ft.

1

in,

out.

flexible.

grid.

Movable

partitions

The plan shows one

possibilities for subdivision within the grid. 1

Lift hall

2

Small reception room

3 Large office 4 Small offices 5 Grid of 3 feet

1

inch x 3 feet

1

inch on which the partitions are based

6 Ladies' cloakroom 7

Gentlemen's cloakroom

8 Internal staircase 9 Vertical service ducts, air-conditioning ducts, escape stairs and 10 Balcony giving access to escape stairs and 1

Lifts for

the delivery of post

lift

lift

can be

of the

many

4 Plan of shuttering.

U

./'

16

5

Diagram

reinforcement (section and plan) of a post-tensioned beam.

of typical

In

beam has also ordinary mild steel the beam only. The post-tensioned

addition to the post-tensioned reinforcements the

bars which are dimensioned to take the weight of

reinforcements are put under stress after the removal tensioning serves

in

addition to increase Ihe

which has a clear span the

beam from

6'/;

of 79 feet,

Of special interest

is

of the shuttering.

at the

in

the

beam

Axis of symmetry

2 Pre-stressed bars

3 Openings for service ducts and pipes

support

The

of the

post-

beam

the variation of the width of

inches to 2 feet to cater for the variation

shear force. The openings 1

moments

in

bending moment and

are for service ducts and pipes.

6 Section between the centre supports. Access to the

The

visitors enter

+

level

3.60 {12 feet) above the car park (below are

seating600people).The

staff

down

to level

the help of a goods

(—24

through two

floors.

J^ ///

lift

—4.90 (—16

delivery

of

in

levels.

front of the station, at

workshops and an auditorium

The access road passes

parallel to

where there is a delivery entrance. With vans or even lorries can be taken down to level —7.55

feet 9 inches) to the service

upper

from three different

enters at the rear of the building at level +0.10(4 inches)

crossing the ramp of the access road by a bridge. the building

7 Section

lifts is

from the Piazza Duca d'Aosta, the square

feet}

rooms.

the centre supports which branch out and taper otT

in

the

Design for a bridge over the Tenza - 1955 Nervi's main consideration in this project

was

to

reduce

scaffolding as the height of the road crossing the bridge

The bridge is These can be erected consecutively with the same

to a

is

minimum

the necessary

164 feet above the valley.

supported by a series of reinforced concrete trestles at intervals of 164 feet.

The road structure The internal spans are simply supported with special connections to the cantilevered beams. They are hoisted into position with the help of winches attached to the trestles. The stiffness of the bridge is achieved through the stability of each individual trestle. The pre-cast scaffolding.

consists of main beams, with cantilevered ends, supported by the trestles.

beams are 1

carried on rollers

Elevation of bridge.

and thereby allow

for

any movement due

to settlement.

2 Horizontal section AA, cross section

concrete trestle.

BB and

longitudinal section

CC

of a reinforced

135

3

Diagram showing

typical reinforcement.

Design for the "Centre National des Industries et Techniques"

in

Paris -1955

Architects: Camelot, de Mailly, Zehrfuss

Engineer; Pier Luigi Nervi

Consulting engineer for the structural steelwork: Jean Prouv6

The great

Exhibition Hall of the projected Centre at the «Place de la

permanent as well as periodical

for

hall covering

exhibitions.

The whole

D6fense»

picture of the

hall. The sides

model shows the extraordinary boldness

are 738 feet

in length.

The height at the top

beams hold the springing pointsofthethreearches is

of

of

the side walls

together.

site.

the construction of the is

158 feet.

The structural

The

calculation

not based on tha thaory of shell construction, but on the principle of the cross-vault-

ing.

The

principal structure consists of three intersecting arches with dia-grid vaulting

between the main

ribs. The use economic considerations.

1

be

an equilateral triangular area and smaller adjoining buildings. The

triangular plan form has been partly dictated by the shape of the available

The

is to

project consists of a large

of prefabricated units for the vaults

Model seen from the south-east.

was favoured by

2 Section

3

through the east-west

axis.

See A-B of plan below). The south-west elevation.

4 Plan of ground floor at level (182.00 1

+

55,50

ft,)

Vertical ducts

2 Information kiosks

3 Stairs 4 Escalators 5

Goods

lifts

6 Lobbies 7

Goods

lifts

and

8

Goods

lifts

and

stairs for the fire

9

Goods Goods

lifts

and

stairs for the post

10

lifts

and

stairs for the

11

Customs

stairs to the kitchen

brigade

Red Cross

office

Of special interest

The glass

is

is

the aesthetic and structural solution of the enormous curtain walls.

fixed to vertical tubular supports

which are

order to

at 30 feet centres. In

provide the necessary stiffness to counteract horizontal wind forces a vertical truss

formed

of tubular

By

means

this

a very light and elegant form

bearing. Between the horizontal

walks and

is

supports and tension bars which are positioned by horizontal struts.

members

is

achieved. The curtain walls are non-load-

of the vertical trusses there

is

room

for cat-

brise-soieils.

5 Vertical section

through the curtain wall. The height

of the tubular truss

is

158 feet.

6 Horizontal section through the curtain wall Between two tubular trusses. Below the

cat-walk and above the adjustable

brrse-so/ei/s.

7 Detail of roof construction at tfie intersection of the arches. J

A node 1

point of the vauitin'

Pre-stressed concrete

2 Prefabricated elements of «ferro-cementow 9 Section through a prefabricated element. 10 Plan, section and various cross-sections through the structure, a

Thickness

of slab

approximately

3'/»

b Approximate outline of foundations c Tie 11

View

beam of structural

model from above.

inches

1

Design for a large Exhibition Centre The

building consistsof a central

circular walk of 246 feet width circular walk are stores

through a central roof will

is

through

its

in

Caracas - 1956

hall of

placed.

590 feet

The

in

diameter, around which a low

The covered area

and garage space for

light.

be constructed with the help

rigidity

domed

3,tXX) cars.

is

972,000 sq.ft, Below the

The

lighting of the hall is

roof structure of the circular walk of

movable shuttering. The dome

prefabricated units above which

is

a roof

is

corrugated and

will

membrane

have structural of further pre-

fabricated units in «ferro-cemento» for thermal insulation and weather proofing.

The

central hall with the

dome

of

prefabricated units.

2 Interior perspective of the circular walk.

'

3 Plan and section.

M M I

^ ^

Acknowledgement F.

Barsotti. Via Scala

to Photographers

4,

Firenze

5, 6. 7, 9,

Folo A. Cartoni, Via Michele

10, 11, 12, 13, 14, 15

Roma VIH Lando 48-54. Roma 19,

Bosio - Pressphoto, Piazza Barberini di

2,

20

Foto Casali, Milano 128 Foto Cresla, Piazza Principe 4-6, Genova 55

Foto-Studio Davio-Bazzan, Via

Lucien Hefv6,

11

B, Miniali, Livorno

Rue Soyer,

E,

De Amicis. Tortona

Neuilly

s.

80(1)

111, 113, 114, 115, 118, 121, 122, 123

Seine

52

Foto Moisio, Gall. S. Federico, 16, Torino 62, 65 Foto Riccardo Moncalvo. Via Ponza,

2,

Torino

68

(12),

59. 63

(18),

69

(7, 8, 9),

(19), 70,

66, 67,

69

73

(30), 93,

(20), 72,

73

94 (29),

74, 75, 81

Pier Luigi Nervl, Lungatevere

Arnaldo da Brescia,

Foto Panizzon, Socchieve (Udine) 82 Foto

P. Pollini,

Pordenone 82

Foto Oscar Savio, Via

(3).

di Pistra,

Foto Vasari, Via Condotti 39,

83

82a,

Roma

(2, 4),

Bologna

79(1),

9,

Roma

48,

49

(6).

79

(2)

(7)

(6)

Roma

89,

3, 26, 27, 28,

43, 49{7). 50, 51,63, (6), 65(11), 78. 80(2), 88,

FotoVillani,

83

84,85,86.95

92 30, 31, 32, 33, 34

(1), 37,

38, 39, 40, 41

90.91.99, 105, 124, 125,126, 127, 139

,

42,

UNIVERSITY OF FLORIDA

^

1262

05437

Date Due Returned APR

1

JUL 2 2

20J

200! _

m

nZOSi LB 27

,1m 2006

6461

^=