Babbage, Charles (1792-1871)

English mathematician who devised a precursor of the computer. He designed an analytical engine, a general-purpose mechanical computing device for performing different calculations according to a program input on punched cards (an idea borrowed from the Jacquard loom). This device was never built, but it embodied many of the principles on which digital computers are based.

Babbage was born in Totnes, Devon. As a student at Cambridge, he assisted John Herschel with his astronomical calculations and thought they could be better done by machines. His mechanical calculator, or difference engine, begun in 1822, which could compute squares to six places of decimals, got him a commission from the British Admiralty for an expanded version. But this project was abandoned in favour of the analytical engine, on which he worked for the rest of his life. The difference engine could perform only one function, once it was set up. The analytical engine was intended to perform many functions; it was to store numbers and be capable of working to a program. The first computer printer, also designed but never built by Charles Babbage, was completed and put on show at London's Science Museum in April 2000.

A Swede, Pehr Georg Scheutz, built a simpler version of the difference engine 1854, which worked and was bought by the Dudley Observatory, Albany, New York (and is now in the Smithsonian Institution).

Babbage was a founder member of the Royal Astronomical Society, the British Association, the Cambridge Philosophical Society, and the Statistical Society of London. He was elected Fellow of the Royal Society in 1816. His book On the Economy of Machinery and Manufactures (1832) is an analysis of industrial production systems and their economics.

In 1991, the British Science Museum completed Babbage's second difference engine (to demonstrate that it would have been possible with the materials then available). It evaluates polynomials up to the seventh power, with 30-figure accuracy.