Groesbeck's Adding Machine

John Groesbeck (1834-1884) from Philadelphia was a consulting accountant, who was many years a teacher and a principal of Crittenden's Philadelphia Commercial College. He is also known as the author of several books, for instance The Crittenden commercial arithmetic and business manual. Designed for the use of merchants, business men, academies, and commercial colleges, published in Philadelphia in 1867.

On March, 1st, 1870, he was granted a US patent No 100288 for Adding Machine (see the lower patent drawing).

The patent drawing Groesbeck's adding machine

The adder of Groesbeck was not of original construction. Similar devices were made earlier by David Roth (in 1842) and patents for such devices were granted to John Campbell (US pat. No 24990) in 1859, and Thomas Strode (US30264) in 1860.

The machine was advertised in newspapers in 1870s (see the lower image) and was manufactured and sold by the company Ziegler & McCurdy, Philadelphia, however, it was never widely sold and production was soon ceased. The original patent was with 2 digital positions only, but actually the machine was manufactured with more, usually 5, digital positions.

Groesbeck's Adding Machine (an advertisement drawing)

The device of Groesbeck had 5 dials and corresponding result digits, numbers can be added into any one of the dials. The device hadn't clearing mechanism, and can be used not only for addition, but for subtraction also.

The wheels are set by means of a pointer, which is placed in the concentric slots c, c' and c'' of the cap-plate in the figure 1 from the patent drawing. The result can be seen in the windows d. Actually there are two rows of result windows, one for adding and another for subtracting.