History of Computing SeriesEditor MartinCampbell-Kelly,UniversityofWarwick,Coventry,UK AdvisoryBoard GerardAlberts,UniversityofAmsterdam,Amsterdam,TheNetherlands JackCopeland,UniversityofCanterbury,Christchurch,NewZealand UlfHashagen,DeutschesMuseum,Munich,Germany JohnV.Tucker,SwanseaUniversity,Swansea,UK JeffreyR.Yost,UniversityofMinnesota,Minneapolis,USA TheHistoryofComputingseriespublisheshigh-qualitybookswhichaddressthehistoryofcomputing, withanemphasis onthe‘externalist’ viewofthis history, more accessibletoawideraudience.The seriesexaminescontentandhistoryfromfourmainquadrants:thehistoryofrelevanttechnologies,the historyofthecorescience,thehistoryofrelevantbusinessandeconomicdevelopments,andthehistory ofcomputingasitpertainstosocialhistoryandsocietaldevelopments. Titlescanspanavarietyofproducttypes,includingbutnotexclusively,themedvolumes,biographies, ‘profile’books(withbriefbiographiesofanumberofkeypeople),expansionsofworkshopproceedings, generalreaders,scholarlyexpositions,titlesusedasancillarytextbooks,revivalsandneweditionsof previousworthytitles. Thesebookswillappeal,varyingly,toacademicsandstudentsincomputerscience,history,mathematics, businessandtechnologystudies.Sometitleswillalsodirectlyappealtoprofessionalsandpractitioners ofdifferentbackgrounds. Authorguidelines:springer.com>Authors>AuthorGuidelines Forothertitlespublishedinthisseries,gotohttp://www.springer.com/series/8442 Charles Care Technology for Modelling Electrical Analogies, Engineering Practice, and the Development of Analogue Computing Dr.CharlesCare Dept.ComputerScience UniversityofWarwick CoventryCV47AL UK [email protected] ISBN978-1-84882-947-3 e-ISBN978-1-84882-948-0 DOI10.1007/978-1-84882-948-0 SpringerLondonDordrechtHeidelbergNewYork BritishLibraryCataloguinginPublicationData AcataloguerecordforthisbookisavailablefromtheBritishLibrary LibraryofCongressControlNumber:2010930604 ©Springer-VerlagLondonLimited2010 Apartfromanyfairdealingforthepurposesofresearchorprivatestudy,orcriticismorreview,asper- mittedundertheCopyright,DesignsandPatentsAct1988,thispublicationmayonlybereproduced, storedortransmitted,inanyformorbyanymeans,withthepriorpermissioninwritingofthepublish- ers,orinthecaseofreprographicreproductioninaccordancewiththetermsoflicensesissuedbythe CopyrightLicensingAgency.Enquiriesconcerningreproductionoutsidethosetermsshouldbesentto thepublishers. Theuseofregisterednames,trademarks,etc.,inthispublicationdoesnotimply,evenintheabsenceofa specificstatement,thatsuchnamesareexemptfromtherelevantlawsandregulationsandthereforefree forgeneraluse. Thepublishermakesnorepresentation,expressorimplied,withregardtotheaccuracyoftheinformation containedinthisbookandcannotacceptanylegalresponsibilityorliabilityforanyerrorsoromissions thatmaybemade. Coverdesign:eStudioCalamar Printedonacid-freepaper SpringerispartofSpringerScience+BusinessMedia(www.springer.com) ForRachel Preface This book is based on research I undertook for my Ph.D. at the University of Warwick. Its motivation began when, as an undergraduate, I completed a research project on the history of planimeters and mechanicalintegrators.That project was my first journey into the history of analogue computing, and left me with more unansweredquestionsthanIstartedwith.Iwantedtounderstandtherelationshipbe- tweenanalogueanddigitalcomputing,andwhatthatmeantforcontemporaryusers. Ifounditfascinatingthatsomehistoriansportrayedanaloguecomputingsolelyasa precursortodigital,whereasotherswerestressingthatanaloguecomputingexisted wellafter1940.Earlyoninmyresearchitbecameclearthathistorianshaddifferent views of the core identity of analogue computing. In fact, it quickly became evi- dentthatevenwithincontemporarysources,therewasaspectrumofunderstanding aroundwhatconstitutedanaloguecomputing.ItwasatthatpointIbeganrestructur- ingthehistoryaroundhowthetechnologywasused. This study investigates the technologies, the concepts, and the applications of analoguecomputing.Itisarguedthatanaloguecomputingmustbethoughtofasnot just a computing technology, but also as a modelling technology. The first half of thebookdemonstrateshowthehistoryofanaloguecomputingcanbeunderstoodin terms of the two parallel themes of calculation and modelling, and describes how the technology evolved. The second half of the book focuses on a number of de- tailedcasestudies:examininganaloguemodellinginacademicresearch,oilreser- voir modelling, aeronautical design, and meteorology. Many of these case studies discussso-called‘direct’analogues—analoguecomputersthatusedadirectphysi- calanalogy.Becausetheywerenotusedascalculators,directanaloguesrarelyre- ceiveprominenceincomputinghistory.However,theseweretheanaloguedevices thatpersistedthelongest. Exploring the history in the context of modelling technology encourages us to see analogue computing in terms of its use. Rather than presenting analogue and digitalasalternatives,thisapproachconsidersthemcomplementary.Thechallenge istonotsimplyconsideranalogueanddigitalasseparatetechnologies,buttocon- sider the continuity of practice that spanned the two. This practice was a practice ofmodelling.Thisbookisnotthefirstaccounttoidentifyacloserelationshipbe- tween analogue computing and modellingtechnology.That relationship is evident vii viii Preface in the sources. However, it is my aim to bring that relationship to the forefront of ourhistoriography. The central thesis is to demonstrate that the history of analogue computing is broaderthanjustthetechnologyorthemachines,butmustalsoincludehowitwas usedandapplied.Whenwelookatthehistoryofanaloguecomputing,wefindthat differentpeoplehaddifferentdefinitionsofwhatanaloguemeant.Manyhistoriesof computinghavediscussedhistoricalepisodeswhenusersdebatedtherelativemerits ofanalogueanddigital.However,thisbookproposesthatthese‘debates’shouldbe framed around application rather than technology. Because the dominant applica- tionsofanaloguecomputingwereasamodellingtechnology,thebookarguesthat digital computing only became truly dominant once it too had become a practical modellingtool. Oxford,UK CharlesCare Acknowledgements Theresearchbehindthisbookistheresultofthreeyearsfull-timestudysupported byaresearchscholarshipawardedbytheDepartmentofComputerScience,Univer- sityofWarwick.Thegenesisofthethemeoriginatedinmyundergraduatedisserta- tiononthehistoryofplanimeters,butthetopicresonateswithinterestsintechnol- ogy,science,andmathematics,thatgobackmuchfurther. Among the many who have offered insights, ideas, and encouragement, a few names are salient. Dr. Steve Russ, my Ph.D. supervisor, has worked hard to guide myreadingandwriting.Hehasfosteredinmyworkablendofphilosophy,history, andcomputing,whichhasmadetheexperienceallthemoreenlightening.Similarly, Prof.MartinCampbell-Kelly,hasalwaysprovidedexcellentadviceandsupport. InteractionswithfellowresearchstudentsandacademicsatWarwickhavebeen invaluable. Thanks go to Meurig Beynon, Steve Matthews, Russell Boyatt, Eric Chan, Ant Harfield, Karl King, Dorian Rutter and Ashley Ward. Other historians ofcomputingalsooffered supportandencouragement,specialthanksgotoDavid Anderson,ChrisBissell,JanetDelve,JamesSumnerandDoronSwade.Acknowl- edgement should also be made to Peter Housego and Joanne Burman of the BP archives,JackieBishopandPaulLilleyatEMIArchives,andJaneWessattheSci- enceMuseum.AlanCharlesworth,once‘SeniorHybridProgrammer’atUniversity ofBath,agreedtobeinterviewed;andPaulCeruzzi,PeterLynch,andBrianRandell providedhelpfulcorrespondence. Also, I would like to formally acknowledge the librarians and archivists at the followinginstitutions:LibraryandModernRecordsCentre,UniversityofWarwick; TheBritishLibrary;BristolUniversityLibrary;ImperialCollegeLibrary;theRoyal Society Library; the IET Library; The Bodleian Library; Birmingham Central Li- brary;BirminghamUniversityLibrary;King’sCollegeLondonLibrary;University of London Senate Library; Cambridge University Library; Manchester University Library;andTheNationalArchives,Kew. Inaddition,Iamindebtedtothepeopleandinstitutionswhohavegrantedpermis- sion to reproduce quotations, images and photographs. Credits are acknowledged throughoutthebook,butIamparticularlygratefultotheAssociationforComput- ing Machinery, American Meteorological Society, BP Plc, Cambridge University ix x Acknowledgements Press,EMIPlc,IEEE,theInstituteofPhysics,JohnsHopkinsUniversity,McGraw- Hill, MIT Press, the Royal Society, the SAAB Corporation, and the University of Chicago.ManythanksalsogotoWayneWheelerandSimonReesatSpringerVer- lagwhohaveguidedmethroughtheprocessessurroundingpublication. Finally,thisbookwouldneverhavereachedcompletionwithoutthesupportand encouragement of my family and friends. My parents and sister have always sup- ported my studies. However, special thanks are due to my wife Rachel, who has livedalongsidethisresearch.She,likenoother,hasexperiencedtheupsanddowns ofthisproject,andherongoingloveandsupportaredeeplytreasured.