A: Baltimore, Maryland, United States
In 1886 American American philosopher, logician, mathematician, and scientist Charles Sanders Peirce recognized that logical operations could be carried out by electrical switching circuits. This idea he mentioned in a letter to his former student Allan Marquand.
Prior to receiving Peirce's letter, in 1881-82, inspired by William Stanley Jevons' logical piano, Marquand built a mechanical logical machine that is still exant according to the Wikipedia article on Marquand. Marquand first published a description of his mechanical machine in 1885. After receiving Peirce's letter, in 1887 Marquand "outlined a machine to do logic using electric circuits. This necessitated his development of Marquand diagrams" (Wikipedia article on Allan Marquand, accessed 10-08-2013).
In October 2013 history-computer.com reproduced a circuit diagram for the electromagnetic logical machine in Marquand's archive that was made about 1890. Other than diagrams of this kind there is no evidence that Marchand or Peirce ever built an electrical logic machine.
The Peirce-Marquand communication or collaboration on the use of electrical switching circuits to carry out logical operations is a remarkable precursor of ideas later developed by Claude Shannon in his thesis of 1937.
(This entry was last revised on 02-23-2016.)