Babbage's Difference Engine No 1, 1824-1832.
© Science Museum / Science & Society Picture Library
Rear detail of Babbage's Difference Engine No 1. British computing pioneer Charles Babbage (1791- 1871) first conceived the idea of an advanced calculating machine to calculate and print mathematical tables in 1812, as he wanted to eliminate all the sources of inaccuracy asociated with compiling mathematical tables by hand. The engine was begun in 1824 and asembled in 1832 by Joseph Clement, a skilled toolmaker and draughtsman. It was a decimal digital machine - the value of a number represented by the positions of toothed wheels marked with decimal numbers.