THE REP AIR OF OXFORD'S HISTORIC BUILDINGS, WITH SPECIAL REFERENCE

TO THE DIVINITY SCHOOL AND DUKE HUMPHREY'S LIBRARY

an abundant supply of freestone conveniently close andwith consequent low transport charges. Entire Collegeswere built or rebuilt in this material including Wadham,Or!el, Queen's and University College. Standards ofselection and the quality of the material supplied dete-riorated rapidly, and this was discovered at the OldSchools Quadrangle erected between 1613-24 and wherethe stone used in the ground storey has weathered somuch better than in the upper stages. The greater partsof the original facing of the lower storey of thisbuilding has been cleaned and preserved : in the caseof the western internaI face of the Old SchoolsQuadrangle decayed ribs were replaced by set ting newmaterial into the original stone. Weaknesses in thestaircase enclosures necessitated the introduction ofreinforced concrete wall beams and stanchions at eachsalient angle, alI concealed behind the masonry .

The untrustworthiness of the soft Headington freestonecame to be appreciated by the beginning of the 18thcentury and substitues were sought : Bath appearing inOxford in 1822. The most durable of these, however,was Clipsham stone from Ruthlandshire, introduced bySir Thomas Jackson in 1877, and later used by himfor the repair of he Old Schools Quadrangle.

The Clipsham stone demonstrated its good weatheringqualities and was the material chosen for most of theprojects in the present operation. The careful selectionof the stone at the quarries was undertaken by anInspector (Mr. Upton) provided by the Ministry ofWorks.

Various methods were employed for cleaning. Themasonry was washed by a rig of sm alI spray jetsmounted on the scaffolding and pressurised by smallelectric pumps. This I think proved the most success-ful. Care was needed however to prevent the satura-tion of the walls. Temporary pointing was often foundnecessary before washing commenced. At the OldBodleian bronze electrodes were introduced into thejointing of the inner wall faces in strategic positionsto enable regular measurements of moisture to berecorded and to alert the operators should penetrationoccur .

At Merton College Chapel Professor Baker cleanedthe two beautiful figures flanking the window in theNorth Transept by the application of lime poultices.

When cleaned the figures were then treated with nume-rable applications of pure lime water. This experimentin case-hardening the surface of the stone is being keptunder observation.

An Appeal launched in 1957 drew public attention tothe serious condition of Oxford's soot-encrusted anddecaying Historic Buildings. It stressed the urgent needfor an immediate and substantial programme of repairwithout which architectural detail and the very characterof so many of these fine buildings would be irretrievablylost. The programme which the Appeal Fund succeededin implementing covered most of the University'sancient buildings and the ancient buildings of all of themen's colleges with the exception of Merton, AlI Soulsand Magdalen who financed their programmes fromtheir own resources.To qualify for assistance the buildings had to predate1800 but an exception was made to this rule inthe case of Keble in recognition of Butterfield's work.Eighteen Colleges participated in addition to the mostimportant University buildings which included the Shel-donian, the Old Ashmolean, the Radcliffe Carneraand Radcliffe Observatory, the Divinity School andOld Bodleian Library.The objective in alI cases was to cleanse and preserveas rouch of the original work as was practicable, andwhere replacement was essential to follow with theutmost integrity the original architectural detail.Regrettably an appreciable amount of refacing provednecessary. The reason for this can be traced directlyto the quality of the stone originally used. Untilthe early part of the 19th century practically a}} ofthe stone for the University and College buildings wasobtained from local quarries, mostly from in andaround Headington and Taynton. It may seem para-doxical to say that the best preserved masonry inOxford dates from the early medieval period, whilstthe material which is being replaced today had beenquarried some three centuries later. The best of themedieval stones -Headington hardstone -has provedthe most durable. It was used in the Bell Tower atNew College (1396-7) and for the plinth of nearlyevery ancient building in Oxford. Unfortunately it isno longer available.The Taynton freestone as used by Richard Winchcombein the early 15th century work at the Divinity Schoolevidences the high quality and selection of this attractiveand durable stone.The spate of building which took place at the beginningof the 16th century and onwards, coupled with thetransition to the sophisticated ashlar faced architectureof the Renaissance, combined to produce a demandwhich the old quarries were quite unable to meet. Manynew quarries were opened at Headington affording

23

Fig. 1. -The interior of the Divinity School.

Examples of cleaning and repair can be seen in mostof the Colleges including the Tom Quad at ChristChurch, New College (outer Quadrangle), the OldSchools Quadrangle, the Radcliffe Camera, etc. Appre-ciable areas of refacing took place at the Sheldonian,Wadham College, the Garden Quadrangle at New Coi-

lege.One of the most successful examples of refacing isthe College Library at Christ Church where Portlandstone was used in conjunction with Oipsham. Asanother variant to Clipsham, Purbeck stone wasemployed for the roof of the Muniment Room atMerton College.Towards the latter part of the programme cleaning bydry sand blasting was tried experimentally for partof the Radcliffe Camera and at Hertford and BrasenoseColleges. Whilst this process avoids the saturation ofmasonry , is more speedy and possibly less expensivethan washing, it is not without its drawbacks. It canso easily destroy crisp arrises and ruin carving whenapplied to soft stone. I found it unacceptable for theOld Bodleian : it is a process which should be usedwith the utmost caution.

I now tum to the Divinity School where some interes-ting structural problems were involved. This excep-tionally beautiful building became the nucleus of a17th century complex which now comprises the OldBodleian Library , the Divinity School, ConvocationHouse and Chancellor's Court. Begun in 1423 it wasoriginally intended as a single storey vaulted Hall offive bays. Progress in its building was slow: it was farfrom complete when in 1444 the decision was takento add an upper storey as a new library to houseDuke Humfrey's gift of books. It is presurned that themasonry vault was then abandoned for it is significantthat the but tresses on the south side of the buildingwere completed without proper bonding. Work conti-nued sporadically for in 1479 the building was stilluncompleted, and as it tumed out fortunately so, fora generous gift from Bishop Thomas Kempe made itpossible to revert to the original project of a vaultedroom.The introduction of the splendid vaulted ceiling byWilliam Orchard was contrived with remarkable inge-nuit y, and certainly is a masterpiece. It was designedto support light reading lectems for the chained books.

Fig.2. Probable appaerance of the interior of Duke Humphrey's Library in 1488. (Drawing by R. Pot ter.

Fig. 3. -South elevation of Divinity School with Wrenn'sbuttress extensions.

A drawing by John Bereblock made in 1566 depictsthe form of the building at this date, and it bears avery close resemblance to its smaller counterpart atWinchester College.After only some sixty years of service the DukeHumphrey Library fell a victim to the troubles of theReformation. The books and furniture were dispersed,and for over fort y years the building remained emptyand neg1ected (1 ).ln 1598 Sir Thomas Bodley undertook " to bring thegreat desolate room back into use " then to house

printed books in huge presses. An increasing demandfor additional space resulted in the building of theArts End Library above the Proscholium and theconsequent removal of the east wall of the DukeHumphrey Library. ln 1637 a further extension wasmade to 1he west with the Convocation House andChancellor's Court beneath, and the removal of thewestern end of the Duke Humphrey Library .To make matters worse galleries were slung from the

(1) " Recent Discoveries in the Bodleian Library

MYRES.Dr. I. N. L.

25

roof over Bodley's bookcases. It is hardly surprisingthat this drasticaIly weakened and grossly overloadedstructure began to fail. The south wall which hadbeen founded over rubbish pits inclined outwards.Sir Christopher Wren who was called in in 1700devised a system of iron slings to ease the weight ofthe bookcases from the vaulting, and added extensionsto the but tresses on the south side of the buildingmounted upon ramping arches.This reinforcement appears to have been reasonablysuccessful but it by no rneans cured the trouble forin 1877 Douglas Galton, an eminent Engineer, wasconsulted. He removed the galleries from the DukeHumphrey Library and reconstructed the floor usingcomposite girders of oak trussed with iron. The sub-sequent ad vent of a piped hot water heating systemcaused the tirnbers to shrink and the girders to sagwith the result that the heavy book presses were oncemore bearing upon the delicate masonry vaults. Thefloor indeed flexed like a bridge, and the constantpowdering from the jointing of the vaulting beneathevidenced movement in the masonry .To rernedy this distressing state of affairs I proposedin my report to the University in 1959 that the structureshould be reinforced with an H-frame; reinforcedconcrete stanchions being formed in the but tresses andlinked with new tie beams forming an integral part ofa reinforced concrete floor. This proposaI was confir-med and developed by Mr. E.W.H. Gifford, the Consul-

Fig. 4. -The structural reinforcement of the Divinity School(1963-1964). A reproduction from the Engineer's drawingsembodying the Architect's proposaIs.

Fig. 5. -Divinity School. Structural work in progress. Fig. 6. -The restoration of the south elevation of the DivinitySchool completed.

26

ting Engineer, and it will be seen from his drawing howthe elements and connexions were contrived (2).A contract was arranged with Messrs. Benfield & Loxleyand a crane installed to service aIl sides of the building.The removal of Bodley's bookcases revealed the sha-dows of the former lecterns in the Duke HumphreyLibrary .The first task was the introduction of the reinforcedconcrete lateral wall beams to provide a seating forthe girders spanning the vaulting and connexions forthe stanchions. The underpinning of the masonrywas executed in short lengths with precast concreteprops which were cast into the beams. The steelgirders were introduced through the windows withthe aid of a specially contrived trussed girder for noloading whatever could be permitted on the vaulting.The lower part of the but tresses were taken down andrebuilt to accornmodate the concrete stanchions which

were reinforced with bronze metal. The decaying Wrenbut tresses had served their purpose and were no longerrequired, but the" ramping arches" were preservedand remain below ground level. The south elevationoverlooking the Fellows Garden of Exeter Collegewas thus restored to its original appearance. But thiswas not the end of the structural problems for it wasdiscovered that the delicate fan vaulted ceiling overConvocation Bouse was also showing signs of distress.Bere again heating engineers with reckless abandon hadcut deep chases into the timber floor beams whichsupported the massive Selden End Library. It is littleshort of miraculous that their amateur props builtdirectly on to the thin masonry vault panels did notbring about a total coIlapse.As a result a new floor was constructed with reinforcedconcrete precast beams, and a similar floor provided atthe Arts End. AIl of these floors were provided withtraps to permit the examination of the vaults.The gaIleries, staircases, comices and wall fittings inthe Selden End Library had undoubtedly been disturbedwhen the floor was removed for the introduction of thei) E.W.H. GIFFORD & Peler TAYLOR.

Introduction of the reinforced concrete floors above the vaultsFig.

27

been fully described in " Recent Discoveries in theBodleian Library " presented as a paper to the Society

of Antiquaries by J.N.L. Myres, Esq. LI. D., D. Litt.,D. Lit., F.B.A., Director Bodley's Librarian 1947-65 (3).The conversion of the Proscholium as the principalentrance to the Old Bodleian Library was the finalwork to be undertaken. It involved the cutting ofnew doorways to give access on to existing staircasesand the necessary furnishing.I regret that in this short paper I have been merelyable to touch upon so few projects included in theprogramme. I would, however, draw particular atten-tion to the work at the Sheldonian Theatre and Rad-cliffe Camera. Mr. Arthur Llewellyn Smith, one of theArchitects concerned, will be describing this to theConference during a site visit.

aforementioned masonry vault over the ConvocationBouse which replaced a plastered ceiling, and flyinggalleries had been provided across the end windows.It was decided to effect a restoration based upon adrawing made by David Loggan in 1675.New staircases were concealed behind the wall fittingsto afford acces to each gallery, cornices were replacedand the coffered ceiling received a number of salvageddecorated contemporary panels. Structural repairs wereexecuted to the roof and concrete wall beams intro-duced beneath the wall plates. The decayed ends ofbeams were reinforced with epoxy resin and securedwith steel reinforcement.A generous donation towards the end of the projectenabled the cleaning and repair of the painted panelsin the Duke Bumphrey and Arts End ceilings, thiswork being undertaken by Mrs. Eve Baker and herAssistants.Many important discoveries were made concerning theevolution of the Divinity School and Duke BumphreyLibrary during the building operations, and these have (3) Copies are obtainable at the Old Bodleian Library

Duke Humphrey's Library after restoration (1964).Fig. 8.

28

prime factor in the need for the present programmeof restoration. The rate of decay of the masonryhas been appreciably accelerated by atmospheric pol)u-tion, and as Clean Air Acts may abate a carboncontent in smokeless zones, no steps have so farbeen taken in this country ta deal with the everincreasing menace of fumes from internaI combustionengines. Research in this field, both as regards thesurvival of man and his buildings, cannot therefarebe too strongly advocated.

The structural reinforcement of the lanterns toHawksmoor's Twill Towers at AIl Souls ColIege wilIbe of interest, and this is described in a paper given tothe Institute of Structural Engineers by the ConsultingEngineers, Mr. E. W .H. Gifford and Mr. Peter Tay-lor (4).Among the works to the interior of buildings l wouldparticularly draw attention to the restoration of thedecorated ceiling in Lincoln ColIege Chapel.A record of the entire work resulting from the Appealand other projects undertaken simultaneously is atpresent being prepared for publication, and it is hopedthat in addition technical data, which it will not bepossible to publish, wilI be deposited with the Bodleian

Library.In retrospect the poor quality of the stone used inthe 17th and 18th centuries has undoubtedly been a

Robert POTTER

F.R.I.B.A., F.S.A.

(4) The S1ruc1ural Engineer, Vol. 42, n° 10, October 1964.

Fig. 9. -Se/den End Library prior to restoration.

29

THE DIRECTION OF THE WORKREFERENCES

ARKELL W.J., "Oxford Stone", Faber & Faber.MYRES J.N.K., LI.D., D. Litt., D. Lit., F.S.A., " Recent

Discoveries in the Bodleian Library ".GIFFORD E.W.H., B. Sc., M.I. Struct. E., M.I.C.E., PeterTAYLOR, B. ~., A.M.I.C.E., " The Restoration of Ancient

Buildings ", in" The Structural Engineer ", Vol. 42, nO 10,act. 1964.

Project

UNlVERSrrYBUILDINGS

Architect/Sureveyor in Charge

The University Surveyor,I. Lankester, M.A., A.R.I.C.S.,A.M.T.P.I.

The Clarendon BuidingThe Radcliffe Camera(Basement)The Botanical GardensHolywel1 Music Room

The Sheldonian Dr. W.G. Allen, D. Litt (Oxon)M.A., F.R.I.B.A.A. Llewellyn Smith, M.B.E., M.A.,F.R.I;B.A.

Robert Pot ter F.R.I.B.A., F.S.A.

The Radcliffe Camera(Exterior)The Old Ashmolean

The Divinity SchoolConvocation House andOld Bodleian Libr~The Radcliffe Camera(Interior)St. Mary's Church w. Ernil Godfrey, M.A., F.R.I.B.A.,

F.S.A.

COLLEGES

AlI Souls

Fig. 10. -Selden End Ljbrary after restoration (1963-1964).(Thomas-Photos, Oxford.)

Balliol

Brasenose

Christ Church

Corpus

ExeterHertfordJesusLincolnMagdalenMerton(Muniment Room)New CollegeOrielPembrokeQuc~n'sS. Edrilunds HallS. John'sUniversity CollegeWadham

T.A. Bailey, M.B.E., M.A.,F.R.I.B.A., F.S.A.G~ffrey Beard, A.R.I.B A.Gera1d Banks F.R.I.B.A., Dip. Arch.LiverpoolR.B. Gray, F.R.I.B.A.E. Playne, D.S.C., F.R.I.B.A., A.A.Dipl.R. Tatchell, M. V .O., B.A. (Arch),F.R.I.B.A.K. Stevens, F.R.I.B.A.R.B. Gray, F.R.I.B.A.T.E. Fathers, F.R.I.B:A.K. Stevens, F.R.I.B.A.The Estates BursarThe Estates BursarRobert Potter, F.R.I.B.A., F.S.A.G. Beard, A.R.I~B.A.The Estates BursarPeter Cleverley; F.R.I.B.A.K. Stevens, F.R.I.B,A.K. Stevens, F.R.I.B.A.Sit Edward MaufeR.B. Gray, B. Arch, F.R.I.B.A.Ii.G, Goddard, D.S.O., D.F.C.,A:F.C., F.R.I.B,A., M.A.Robert Potter, F.R.I.B.A:, F.S.A.w. ElnîlGodfrey, M.A., F.R.i.B.A.,F.S.A.

(StaircaSce No.9)Worcester

30

c~

~~.~

cf;~

~

Fig. Il: -A reconstruction of the cast facade of the DivinitySchool and Duke Humphrey's Library. {Drawing by R, Potter.)

ci