Centigraph Adding Machine

Arthur E. Shattuck of San Francisco, California, was a holder of 4 USA and 1 Canadian patents for calculating devices. First (No 268135 from 1882) and second (No 349459 from 1886) patents (received together with Charles Thorn) are for chain adders, which never reached the market. The third (No 363971 from 1887, together with Brainard Smith) and fourth patents (No 453778 on June 9th, 1891) (see the lower patent drawing) however, were for an simple 5 key single-column adder, the second version of which will be manufactured and sold in small quantities in 1890s under the name Centigraph Adding Machine (also Centigraphe and Centagraph) by the company American Adding Machine Co., Atlanta.

The patent drawing of Centigraph Adding Machine

The operation is as follows: Pressing the keys, the plate D is so turned, that through its aperture the ciphers are seen. For the digits over 5 two keys (marked with F) must be presses simultaneously (for instance for 6, 5 and 1 must be pressed), whereupon plate C moves one number to the right, and plate D moves five numbers to the left, and in the aperture figure 6 is seen. The plate can counter to 99, but there is a separate 5 positional pointer for hundreds, which allows the sum to reach 599.

The Centigraph Adding Machine (© 2009 by Auction Team Breker, Cologne, Germany, www.breker.com)