Peter Forrester

Peter C. Forrester's adding machine (the patent drawing)
Peter C. Forrester’s adding machine (the patent drawing)

In 1881 Peter C. Forrester, a mining engineer, living in San Francisco, California, patented (see US patent Nr. 249606) a keyboard adding machine (see the nearby patent drawing). We don’t have further information for this adding device, so obviously it remained only on paper and has been never implemented in practice.

The adding device of Forrester has a framework with an upright portion and a keyboard resembling somewhat an upright-piano. It has dial-plates and indicators adapted to be moved by a clock mechanism and an escapement, an oscillating plate (marked with M), with a groove m for releasing said escapement, in combination with the means for oscillating said plate, consisting of the pinion l, segment K, crank I, upright rod G, crank F, rocking shaft D, with its pins d, and removable keys B, with their adjusted lifters b.

The device has a motor-spring, adapted to be wound up as a clock. The shaft on which it is carries the large gear X, from which motion is transmitted through appropriate gears to the dial or escapement-shaft S and to the shaft which operates the dial-finger Z of the dial-plate recording tens.

In short columns of numbers, the device is not as useful as in long ones. When the latter have to be added the time taken in turning the dials after each row is not noticeable.

Biography of Peter Forrester

Peter Forrester (1858-1952)
Peter Forrester (1858-1952) in 1944

Peter “Pete” C. Forrester was born on 16 June 1858 in Windsor, Ontario, Canada (across the Detroit River from the U.S. city of Detroit), to Peter C. Forrester and Mary White. His family (Peter had a brother and a sister) moved to the United States, and settled in Leavenworth, Kansas, around 1860.

Forrester was a mining engineer with a long career that has taken him from Alaska to Mexico City and the Hawaiian islands and in several western US states like Nevada, California, Arizona, and Washington. Peter C. Forrester was also a prolific inventor and businessman, the author of many (some 36) US and Canadian patents for various inventions like a method of mining coal (US patent 473734), scroll former (US543233), a tool for binding metal strips (US543234), drill (US628404), filtering apparatus (US284495), match-machine (US1041989), automatic door (US786109), and many others.

On 25 July 1900, Peter Forrester married Bessie Lynette Toner (1872-1925) from Detroit, Michigan.

Forrester moved to Tacoma, Washington, in 1888. There he investigated the possibility of getting a better grade of coke for a smelter he operated in Nogales, Arizona, then went to Wilkeson to inspect the mine there and wound up as its superintendent. In 1896 he moved to California, where he developed an ore grinding mill, but later returned to Tacoma, where he bought land, built a house, and continued with his inventions. Forrester died in Tacoma on 5 July 1952, at the age of 94.