What if we had had computers a hundred and fifty years ago? It could have happened. The plans were drawn up for a computer that would have been very much like those of today, except it would have run on cogs, gears, levers, springs, and maybe steam power. We only got around to computers a hundred years later, but things could have worked out much differently, if the work of Charles Babbage had taken off. Doron Swade knows just how well such an engine could have worked. He built one. Or rather, his team within the London Science Museum built a calculating engine that Babbage had designed. It worked, just as Babbage knew it would. Swade tells the story of Babbage and his amazing machines in _The Difference Engine: Charles Babbage and the Quest to Build the First Computer_ (Viking). Babbage's accomplishments turned out to be futile in the end, but Swade shows us how there is much to admire in his quest, successful or not.
Babbage wrote papers on chess, taxation, lock-picking, philosophy, submarines, archeology, cryptanalysis, and many other diverse efforts. He was an unstoppable inventor and tinkerer; he invented (but didn't get credit for) the ophthalmoscope every doctor has used, and the cowcatcher installed on the front of locomotives. But what he loved most of all were his computing machines. The Industrial Revolution was making everything else by steam; why not calculations, and perfect tables of them? He designed just such a calculating engine, and although because of various problems it didn't get built, he never stopped tinkering with it, and he designed an even bigger calculation machine that would have done, in its cogwheel way, all the basics that computers now do.
Babbage is sometimes called the grandfather of the computer, but he is more like an uncle. There is no evidence that any of his intricate and visionary machines influenced the design of electronic computers. Swade's engrossing book gives a good capsule biography of a fascinating man, but more importantly, it shows a hands-on appreciation for the machines he had dreamed up. Babbage knew that his dreams were doomed for his own time, but he had an inkling of what was to come; he wrote of the inventor's lot, "The certainty that a future age will repair the injustice of the present, and the knowledge that the more distant the day of reparation, the more he has outstripped the efforts of his contemporaries, may well sustain him against the sneers of the ignorant, or the jealousy of rivals." He was right again.