Charles Babbage (Image 1) was born to a wealthy London-area banking family in 1791 and, after being educated in a number of schools and by various tutors, he enrolled at Trinity College, Cambridge in 1810. There, he befriended future Victorian science luminaries John Herschel (polymath astronomer and one of the first inventors of photography) and George Peacock (a noted mathematician), with whom he formed the Analytical Society to support the use of Leibniz's calculus over that of Newton.

Babbage was elected a fellow of the Royal Society in 1816, just two years out of Cambridge, and eventually became Lucasian Professor of Mathematics in 1828, a position held once by Isaac Newton and, more recently, Stephen Hawking.

Babbage's life was typical of the 19th century gentleman scientist. Like many of his peers, inherited wealth allowed him to explore his interests and contribute to research in mathematics, astronomy, and engineering.

Babbage's largest project, the Difference Engine no. 1, was a machine intended to save the government money by preventing critical errors in tables calculated and copied by hand. But after twenty years of costly work on his design - in which time he suffered through personal disputes with his toolmaker Joseph Clement and lost his father, wife, and all but three of their eight children - the Difference Engine no. 1 remained uncompleted.

## Difference Engine no. 1

Tables of data generated from polynomial functions were critical for aiding navigation at sea using the lunar distance method of determining longitude. But because such tables had to be calculated by human 'computers', they suffered from errors in both calculation and in transcription and typesetting for the printing process.

Babbage was something of a connoisseur of tables and fastidiously combed through them for errors. During a meeting with Herschel in 1821 to verify calculations made by human computers he lamented,

*"I wish to God these calculations had been executed by steam." Babbage in 1821(1)*

Babbage's idea, hatched over the following two years, was for a device that would reduce the calculation of polynomial functions to mechanical addition using the method of finite differences. The engine would be 'programmed' with a function and cranked by hand to deliver the result. It would also be equipped with a press that would allow results to be printed as they were calculated in real time and replicated on the spot without error.

In 1822 he received funding for the device, called the 'Difference Engine', and hired a toolmaker, Joseph Clement, to build it. The Difference Engine called for nearly 25,000 parts in total, one of the most complicated engineering feats attempted in its day.