Hartree differential analyser, 1935.

The machine shown is approximately half of the original differential analyser known as the Manchester machine. It was built by Douglas Hartree (1897-1958), based on the differential analyser built in 1930 by Vannevar Bush at the Masachusetts Institute of Technology (MIT). A differential analyser consists of a number of interconnecting integrating mechanisms. Its purpose is to provide an analogue method of arriving at a numerical solution to a differential equation.