Dorr Eugene Felt is best known for two inventions, the Comptometer (the first calculator featuring keys to enter numbers rather than dials) and the first printing desk calculator, which was a modified version of the Comptometer.

Dorr Eugene Felt was born in Rock County, Wisconsin, in 1862. The first part of his life was spent living and working on a Rock County farm, and his formal schooling ended after only one year of high school. At the age of 14 Felt started working at a local Beloit machine shop. At the age of 20 Felt moved to Chicago to continue working on machines and to study their design. In Chicago he started work with the Pullman Company on a maintenance crew, eventually being promoted to foreman, a job which he left to become a sewing machine salesman. The life of a travelling salesman was not to be and he soon returned...