The man who invented the computer but never built one

Charles Babbage (1791-1871) was a man of many interests. He achieved notable results in cryptography, invented the cow-catcher for trains and engaged himself in public campaigns against nuisances, including the dangerous practice of boys running their iron hoops underneath horses. Today, he’s most famous for his pioneering efforts in computing. Like Alan Turing, Babbage invented the computer from scratch but never managed to build one. And also like Turing, his intellectual tour de force was only truly recognized after his death.

Over his lifetime, Babbage envisioned several mechanical calculating machines he called engines. The first one, the Difference Engine, was designed to solve polynomial equations using the mathematical technique of finite differences. This method reduces multiplication and division to addition, which is much easier to implement with the rods, gears, levers and linkages that were at the disposal of the Victorian-era gentleman-engineer. Two hundred years ago this week, Babbage presented his first paper on the Difference Engine to the Royal Astronomical Society, kicking off a visionary if troublesome pursuit that inspires awe even today.