JF Ptak Science Books Quick Post
This magnificent image was–is–The Comptometer, a key-driven calculating machine made by Felt & Tarrant Manufacturing Company, a glorious instrument, encased in coppery metal, and just larger than a large shoebox. It was invented by Dorr E. Felt (1862-1930) in 1889, and in order to put his idea into production went into business with the Chicago businessman and entrepreneur Robert Tarrant, and the two made an enormously successful go of the whole operation, the machine being easy to carry, and easy to use, and saved a huge amount of time in calculating mounds of long figures.
The image (and ad, below) both appeared in the November 11, 1893 issue of the Scientific American.
