This model of a differential analyser, which is fully built out of Meccano, was built by Nicholas Eyres while working as a maths teacher at Radley College in Oxfordshire. During the Second World War he had worked at the University of Manchester in a group led by Prof. Douglas Hartree. The model was later restored by Charles Lindsey who made some small improvements to the model and brought it back to working condition.

A differential analyser is a mechanical, analogue computer. Unlike digital computers, which are based on using digits to express numbers, analogue computers use physical measures such as electrical, mechanical, or hydraulic quantities to model the problem being solved. The slide rule is an example of an analogue calculating device but as it can only perform one set of functions, which are set during its production, it is not regarded as a computer. When an analogue device can be “programmed” to perform different functions at different times it can be called an analogue computer.

The differential analyser solves a type of mathematical function called differential equations by integration, using wheel-and-disc mechanisms to perform the integration. The first functional differential analyser was built by Harold Locke Hazen and Vannevar Bush at MIT (Massachusetts Institute of Technology) in the United States between 1928 and 1931. In the following years more machines were built, including one at the University of Manchester which came into operation in 1935 and was used by the team led by Prof. Douglas Hartree. The model, built by Metropolitan-Vickers, an electrical engineering company, was partly built out of Meccano. At the beginning of World War II, the differential analyser at the University of Manchester was the only full-size example in the country. Arrangements were made with the Ministry of Supply to have the machine available for any suitable work that might contribute to the war effort. Nicholas Eyres began working on this project in 1940 as part of a small team working on solving differential equations relating to ballistics and their trajectory, amongst other things.

The differential analyser became obsolete following the invention of the electronic analogue computer, which had largely replaced mechanical computers by the 1950s.

Manufacturer:
Date: Unknown

This exhibit has a reference ID of CH72473. Please quote this reference ID in any communication with the Centre for Computing History.

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