Integraph

An Integraph is a mechanical analog computing device for plotting the integral of a graphically defined function.

[1] A full description of an integraph was published independently around 1880 by both British physicist Sir Charles Vernon Boys and Bruno Abdank-Abakanowicz, a Polish-Lithuanian mathematician/electrical engineer.

[3][4][1] Customized and further improved versions of Abakanowicz's design were manufactured until well after 1900, with these later modifications being made by Abakanowicz in collaboration M. D. Napoli, the "principal inspector of the railroad Chemin de Fer de l’Est and head of its testing laboratory".

Along the trailing vertical (y axis) rail slides a smaller carriage holding a tracing point.

The trailing carriage is connected both with a point in the center of the carriage and the disc on the leading rail by a system of sliding crossheads and wires, such that the tracing point must follow the disc's tangential path.