In 1847 the inventor Charles Babbage drew up the plans for the world's first functioning modern computer. Almost 150 years later in 1989 the British Science Museum spent two years to construct a working model from Babbage's original drawings that still works today. And is a beautiful marvel of precision engineering. [ame=http://www.youtube.com/watch?v=KBuJqUfO4-w]Charles Babbage and his Difference Engine #2 - YouTube[/ame]

Difference Engine A difference engine is an automatic, mechanical calculator designed to tabulate polynomial functions. The name derives from the method of divided differences, a way to interpolate or tabulate functions by using a small set of polynomial coefficients. Both logarithmic and trigonometric functions, functions commonly used by both navigators and scientists, can be approximated by polynomials, so a difference engine can compute many useful sets of numbers. The historical difficulty in producing error free tables by teams of mathematicians and human "computers" spurred Charles Babbage's desire to build a mechanism to automate the process. Difference engine - Wikipedia, the free encyclopedia