Most people think of computers as very (1) modern inventions, products of our new technological age. But actually the idea for a computer (2) had been worked out over two centuries ago by a man (3) called Charles Babbage. Babbage was born (4) in 1791 and grew up to be a brilliant mathematician. (5) He drew up plans for several calculating machines (6) which he called "engines". But despite the fact that he (7) started building some of these, he never finished any of them. Over the years, people have argued (8) whether his machines would ever work. Recently, (9) however, the Science Museum in London has finished building (10) an engine based (11) on one of Babbage's designs. (12) It has taken six years to complete and more (13) than four thousand parts have been specially made. Whether it works or not, the machine will be on show at a special exhibition in the Science Museum (14) to remind people of Babbage's (15) work.