This is the first printed account of the first circuit diagram, prepared in about 1885 by Alan Marquand, for an electrical relay machine that performs logical inference. The complete issue, in wrappers. Some soiling. A very good copy. Octavo. Item #10927
It is usually assumed that the performance of logical inference by electrical relay machines is of comparative recent date. However, Alonzo Church as discovered a wiring diagram among Marquand’s manuscripts, which was not mentioned in any of the published literature and which appears to be the first circuit of an electrical logic-machine. Mays’ paper describes the diagram and explains its operation. “There is no evidence that this version of his device was ever actually constructed.” Marquand (1853-1924), the inventor of a logic diagram that carries his name, constructed a mechanical logic machine that was the first real advance over that of Jevons. (M. Gardner, Logic Machines and Diagrams, p. 125).