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Babbage, Charles

time mathematics engine cipher

(1791–1871) British mathematician and computer scientist: inventor of the programmable computer. As the talented child of affluent parents, Babbage entered Cambridge in 1814 to study mathematics. He and his friend put effort into spurring their teachers to achieve a better standard in mathematics teaching, translating continental textbooks for their use and advocating calculus notation rather than . Babbage became professor of mathematics in Cambridge in 1828, and worked on the theory of functions and on algebra. However, he soon concerned himself with the poor quality of the mathematical tables then available, which were rich in errors, and blamed for many shipwrecks and engineering disasters. He was convinced that mechanical calculation could give error-free results; the subject became obsessive for him and was ultimately to change him from a sociable young man into an irascible elder who clashed even with the street musicians whose activities, he claimed, ‘ruined a quarter of his work potential’.

After making a small-scale mechanical calculator in 1822, Babbage designed his ‘Difference Engine No 1’, which was to perform arithmetical operations using toothed wheels. Hand-powered, it was to work on decimal principles – the binary system is logically linked with electronics and was yet to come. Over 10 years later, in 1833, the project was abandoned with only 12 000 of the 25 000 parts made and the then large sum of £17 470 expended, sufficient to build two battleships at the time. , the Astronomer Royal, pronounced the project ‘worthless’ and the Government withdrew its support. A modest section of the engine with about 2000 components, made as a demonstration piece in 1832, works impeccably to this day and is the first known automatic calculator.

Babbage promptly began to design a more advanced ‘Analytical Engine’ and worked on this until his death. It was to have a punched card input, a ‘store’ and ‘mill’ (equivalent to the memory and processor in a modern computer) and would give a printed, punched or plotted output. Construction of its 50 000 geared wheels, to be mounted on 1000 vertical axles, never began in Babbage’s time. In the late 1840s he also planned a simpler and more elegant calculator (‘Difference Engine No 2’) to work with numbers up to 31 digits, but could not get government support for either machine.

In 1985 the Science Museum in London began to build, in public view, Difference Engine No 2. Its 4000 bronze, cast iron and steel components were assembled to make the 3 ton machine with only modest changes in Babbage’s design. It was completed in time for the Museum’s exhibition commemorating his 200th birthday; its first full-scale calculation was to form the first 100 values in the table of powers of 7, and it has operated without error ever since then. It cost nearly £300 000. Its automatic printer is still to be built.

Babbage was assisted in his work by Ada King, Countess of Lovelace (1815–52), the daughter of the poet Byron, who spent much time assisting him and publicizing his work; the best account of Babbage’s views on the general theory of his ‘engines’ is due to her and the US Defense Department programming language ADA is named for her. The two of them also tried to devise a system for predicting the winners of horse races (she was a fearless horse-woman) and lost money in the process.

However, Babbage worked not only in mathematics, statistics and computing, but also on climatology (using tree-rings as historic climatic records), the theory of what we would now call mass production and operational research, and also cryptanalysis, or codebreaking. He gained a reputation for the latter by deciphering a number of secret historical documents, including the shorthand notes of the astronomer , and a cipher used by Henrietta Maria, wife of Charles I. In 1854 he also devised a method of breaking the Vigenère cipher, a polyalphabetic cipher first devised by the French diplomat Blaise de Vigenère in 1586, but still widely used in the 19th-c for military and diplomatic purposes because of its apparent impregnability.

Babbage, Charles - Overview, Personal Life, Career Details, Social and Economic Impact, Chronology: Charles Babbage [next] [back] Babatunde, Obba

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