Editing Differential analyser (section)

==Use of Meccano==
[[Image:DA Cambridge c1937.jpg|thumb|[[Museum of Transport and Technology|MOTAT's]] Meccano differential analyser in use at the Cambridge University Mathematics Laboratory, c. 1937. The person on the right is [[Maurice Wilkes|Dr Maurice Wilkes]], who was in charge of it at the time|alt=]]
The model differential analyser built at Manchester University in 1934 by Douglas Hartree and Arthur Porter made extensive use of [[Meccano]] parts: this meant that the machine was less costly to build, and it proved "accurate enough for the solution of many scientific problems".<ref name=CamDA>{{harv|Hartree|Porter|1934–1935}},{{cite web|url=http://amg.nzfmm.co.nz/differential_analyser.html|title= Differential Analyser |access-date=2010-07-21|publisher=Auckland Meccano Guild}}</ref> A similar machine built by J.B. Bratt at Cambridge University in 1935 is now in the [[Museum of Transport and Technology]] (MOTAT) collection in [[Auckland]], [[New Zealand]].<ref name=CamDA/> A memorandum written for the British military's Armament Research Department in 1944 describes how this machine had been modified during World War II for improved reliability and enhanced capability, and identifies its wartime applications as including research on the flow of heat, explosive detonations, and simulations of [[transmission lines]].<ref>Cairns, W. J., Crank, J., & Lloyd, E. C. ''Some Improvements in the Construction of a Small Scale Differential Analyser and a Review of Recent Applications'', Armament Research Department Theoretical Research Memo. No. 27/44, 1944 (see {{Cite web|last=Robinson|first=Tim|title=Bibliography|publisher=Tim Robinson's Meccano Computing Machinery web site|date= 2008-06-07|url=http://www.meccano.us/bibliography.html|access-date=2010-07-26}}). The memorandum is now in [[The National Archives (United Kingdom)|The National Archives]], UK:

{{Cite web|title=Piece reference DEFE 15/751|publisher=The National Archives
|url=http://www.nationalarchives.gov.uk/catalogue/displaycataloguedetails.asp?CATLN=6&CATID=1926821&j=1|access-date=2010-07-26}} For the "Armament Research Department", see [[Fort Halstead]], and cf. the entry for 1944 in {{Cite web|title=MoD History of Innovation|publisher=Ploughshare Innovations Ltd|url=http://www.ploughshareinnovations.com/about/MoD_full_history.pdf|access-date=2010-07-26}}</ref>

It has been estimated, by [[Garry Tee]] that "about 15 Meccano model Differential Analysers were built for serious work by scientists and researchers around the world".<ref>Irwin, William (2009-07). ''Op. cit.'' "It is estimated by Garry Tee of Auckland University that about 15 Meccano model Differential Analysers were built for serious work by scientists and researchers around the world." For Garry Tee, see {{cite web|url=http://www.cs.auckland.ac.nz/historydisplays/MoreOnDisplays.php|format=php|title= Computing History Displays: The Displays |access-date=2010-07-22|publisher=University of Auckland}}</ref>