JF Ptak Science Books Quick Post
I’ve looked around quite a bit now and without success about this calculator designed by Thomas Gray–except for this small notice in Popular Mechanics. “Electric Brain Solves the Hardest Problems” pops up in the September 1931 issue of Popular Mechanics, and is a nice description of the machine:
Bush, V. (October 1931). “The differential analyzer. A new machine for solving differential equations”. Journal of the Franklin Institute 212 (4): 447–488
Notes:
Thomas S. Gray (1906-1992) “was professor emeritus of engineering electronics at M.I.T… best known for the development in 1931 of the Photo-Electric Integraph, a calculating machine that solved complex mathematical problems in minutes by turning them into rays of light…out of this work came his book “Applied Electronics,” an authoritative text, published by M.I.T. Press in 1954.–New York Times 1992 obituary