Print head from Babbage's Difference Engine No 2, 2000.
© Science Museum / Science & Society Picture Library
Detail of the print head (large font) from Babbage's printing and stereotype apparatus. Babbage's Difference Engine No 2 was constructed by the Science Museum in London from drawings made by the British computing pioneer Charles Babbage (1791-1871) between 1847 and 1849. The main part of the engine was completed in 1991 for the bicentennial year of Babbage's birth, and the printing mechanism was completed in 2000. Babbage conceived the engine to calculate a series of numerical values and automatically print the results.