The Computer That Never Was–Now Is!

Wired Magazine’s Gadget Blog reports that researchers have actually built a working version of Charles Babbage’s difference engine. Click through the link to see video of the engine in operation.

Charles Babbage completed plans for an elaborate, all-mechanical calculator in 1849. His Difference Engine #2 was so complicated, with more than 8,000 separate parts, that it was never built during his lifetime. But now, thanks to the efforts of dedicated, historically-minded engineers at the Computer History Museum in Mountain View, California, plus a generous donation of cash from Microsoft gazillionaire genius Nathan Myhrvold, Babbage’s Difference Engine is on display in Silicon Valley.

It works. The five-ton bronze, steel and cast iron contraption is operated by a crank handle and can calculate the results of elaborate trigonometric and logarithmic functions with 31 digits of precision. What’s more, it has a printer which stamps the results of its calculations on paper and on a plaster tray, which could be used to create lead type for printing books of mathematical tables.

That’s just unbelievably cool. What a great piece of history to bring to life!

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Alex Knapp
About Alex Knapp
Alex Knapp is Associate Editor at Forbes for science and games. He was a longtime blogger elsewhere before joining the OTB team in June 2005 and contributed some 700 posts through January 2013. Follow him on Twitter @TheAlexKnapp.


  1. anjin-san says:

    Very cool indeed…

  2. DL says:

    Too bad it wasn’t fuctional in his day. Maybe someone woulod have used it to calculate the astronomical number of deaths that would be caused if they started the world’s deadliest oxymoron – the Civil War.

  3. sam says:

    Fro more along these lines, Google ‘Antikythera mechanism’. Pretty smart those ancient Greeks.

  4. William d'Inger says:

    Talk about a day late and a dollar short. Some British museum built and operated a model #2 Babbage Difference Engine nearly 20 years ago. I read about it in Scientific American or Popular Mechanics or some similar magazine. I suppose it’s alright to re-invent the wheel when people have short memories.

  5. Alex Knapp says:


    Yes, the London Museum of Science built one back then. They also built this current model. It’s in the video in the article I linked to, but I’m sorry for the confusion.