Babbage's Difference Engine No 1, 1824-1832.
© Science Museum / Science & Society Picture Library
British computing pioneer Charles Babbage's (1791-1871) Difference Engine No 1 was the first succesful automatic calculator and remains one of the finest examples of precision engineering of the time. It was a decimal digital machine - the value of a number being represented by the positions of toothed wheels marked with decimal numbers. The portion shown here was asembled in 1832 by Babbage's engineer, Joseph Clement. It consists of about 2000 parts and represents one-seventh of the complete engine. This 'finished' portion of the unfinished engine was demonstrated to some acclaim by Babbage and functions impeccably to this day.