Dorr Felt

Dorr Felt (1862-1930) was an American inventor and entrepreneur who fundamentally transformed business mathematics through his innovation of the Comptometer. The Comptometer, patented in 1887, was among the first key-driven mechanical calculators and became the standard computing device for accounting and business operations throughout the late 19th and 20th centuries. Felt's invention allowed operators to input numbers directly via keys rather than using slower mechanical systems, dramatically increasing computational speed and efficiency. He founded the Felt & Tarrant Manufacturing Company to produce and market his invention, which became enormously successful and influential in business circles. The Comptometer remained in widespread use for decades, with versions of the machine continuing to operate in accounting departments well into the computer age. Felt's legacy represents a crucial bridge between manual calculation and the modern digital computing era, establishing principles of efficient data input that remain relevant today.