Homeostat

After a few technical hiccups with short-circuits causing burn-outs, the homeostat was finally completed on 16 March 1948.

[1] It was an adaptive ultrastable system, consisting of four interconnected Royal Air Force bomb control units[2] with inputs, feedback, and magnetically driven, water-filled potentiometers.

It illustrated his law of requisite variety[3] — automatically adapting its configuration to stabilize the effects of any disturbances introduced into the system.

[5] When Alan Turing heard of Ashby's intention to build the homeostat, he wrote to Ashby to suggest that he could run a simulation on Turing's Automatic Computing Engine (ACE) instead of building a special machine.

[6] The first published account of the homeostat appeared under the title of "Design for a Brain" in the December 1948 issue of 'Electronic Engineering',[7] where he speculates about a perfected homeostat that could eventually play chess "with a subtlety and depth of strategy beyond that of the man who designed it."