Landin's Computing machine

Landin's Computing machine is a chain adder of the type, invented in 1670s by Claude Perrault.

The Landin's Computing machine patent drawing

It was invented around 1890 by Peter J. Landin from Minneapolis, Minnesota, which received a US patent No 482312 on 6th of September, 1892 (see the upper patent drawing).

The device (see the nearby photo) was manufactured from 1891 by the company of the inventor—Landin Computer Co., Minneapolis, under the name Landin Computer. Later in the end of 19th and the beginning of 20th century it was produced by the Rapid Computer Co., Minneapolis, under the name Rapid Computer. Later in 1920s an improved version was manufactured by Hans Sabielny, Dresden, Germany, under the name Comptator. The price in the beginning of 20th century was $25.

The Landin Computer is a seven digital positions slide-chain adder operated with pin or pencil. It is a well designed and manufactured device, with robust and reliable construction. It had a good market success, especially the Comptator of Sabielny in Europe.