The differential analyser was a mechanical analog computer invented by Vannevar Bush in 1927. It is designed to solve differential equations by integration, using wheel-and-disc mechanisms to perform the integration.

The differential analyser was used in the development of the bouncing bomb, used to attack German hydroelectric dams during World War II. Differential analysers have also been used in the calculation of soil erosion by river control authorities. It was eventually rendered obsolete by electronic analog computers and later digital computers.

More recently, building differential analysers out of Meccano has become a popular project among serious Meccano hobbyists.

External links

• Vannevar Bush bio (http://www.kerryr.net/pioneers/bush.htm) which focuses on the Differential Analyser
• Differential Analyser (http://scoter2.union.edu/~hemmendd/Encyc/Articles/Difanal/difanal.html)
• Vannevar Bush's Analog Computer (http://www.maxmon.com/1927ad.htm)
• The Differential Analyser Explained (http://www.dalefield.com/nzfmm/magazine/Differential_Analyser.html)
• Tim Robinson's Meccano Differential Analyser (http://www.meccano.us/differential_analyzers/robinson_da/index.html)