Origin of modern calculating machines

by J. A. V. Turck

The Early Key-Driven Art

M. Le Colonel D’Ocagne, Ingénieur des Ponts et Chaussées, Professeur à l’École des Ponts et Chaussées, Répétiteur à l’École Polytechnique, in his “Le Calcul simplifie,” a historical review of calculating devices and machines, refers to the key-driven machine as having first made its appearance in the Schilt machine of 1851, but that the Art reached its truly practical form in America. In the latter part of his statement the professor is correct, but as to the first appearance of the key-driven machine the U. S. Patent Office records show that a patent was issued to D. D. Parmelee in 1850 for a key-driven adding machine ([see illustration]).