Integraph
![Coradi of Zurich's integraph, 1911 drawing](/Images/godic/202501/20/Calculating_machines_224146.png")
An Integraph is an instrument used in mathematics for plotting the integral of a graphically defined function.
It was invented independently about 1880 by the British physicist Sir Charles Vernon Boys and by Bruno Abdank-Abakanowicz, a Polish-Lithuanian mathematician/electrical engineer from the Russian Empire. Abakanowicz's design was constructed by Coradi of Zurich.