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Babbage's Difference Engine

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Babbage's Difference Engine

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Babbage's Difference Engine

In 1822, Charles Babbage began to try to find a way of mechanising, and making more accurate, the production of mathematical tables. He called the machines he designed difference engines, but owing to lack of funding and the inadequacies of contemporary mechanical engineering processes, none was ever completed during his lifetime.

In 1985, the Science Museum undertook to build one to his specifications, to discover if the machine would actually work. They chose to create Difference Engine Number 2, the plans for which dated from 1847-9. The machine is huge: it has more than 4000 components made of cast iron, steel and bronze and weighs 2.6 tonnes. It is ten feet wide and six feet tall – hardly a practical alternative to a pocket calculator! However, when the handle was finally cranked on this contraption and it performed its first sequence of calculations, the answers produced were to 31 digits of accuracy, more precise than any standard calculator. For his work on the Difference Engines, along with his more sophisticated Analytical Engines, Babbage is rightly celebrated as a pioneer in the history of computing.

Photo: Courtesy of The Science Museum


Your comments

This is a salute to British Eccentricity. In 1822 Charles Babbage was a mathematician who conceived of a machine to automatically perform Mathematical calculations. He came up with the Difference Engine and the Analytical Engine, widely seen as the grandfather of the Computer. Babbage never completed his machines largely on account of him not being able to stop himself fiddling with the design. But a replica built in the 1980's proved that the Difference Engine did in fact work.

Paul Brandon

Actually, the Difference Engine is less an ancestor of modern computers than a distant cousin. The modern inventors of electronic digital two-valued general purpose stored program computers did not study Charles Babbage's notes on how to build a mechanical Difference Engine. Still, it *is* an icon. After all, Microsoft's former technology director, Nathan Myhrvold, got one for his home, complete with Babbage-designed mechanical printer, in exchange for sponsoring the one at the Science Museum.
David Tonhofer

Charles Babbage was my great great great grandfather on my fathers side of the family...I am very excited that he invented the basis of the part of the computer that we now use everyday..My sister Lorna Babbage is a mathametics major in Chilliwack B.C. The difference engine was not built until the 1990 because he pieces to complete it were not available when Charles Babbage invented his two engines. If you check the Science Museum in London you may see the working model of his engine.
Catherine Anne Babbage

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I believe rice, peas and jerk chicken is an Icon of England.

Ade Adeluwoye