Babbage difference engine No. 2 now operational


Moon-mad steampunk engineers have constructed Charles Babbage's Difference Engine No. 2 from the master's original plans. It is now on display at the Computer History Museum in Mountain View, Calif., after being completed last month.

"The first complete Babbage Engine was completed in London in 2002, 153 years after it was designed. Difference Engine No. 2, built faithfully to the original drawings, consists of 8,000 parts, weighs five tons, and measures 11 feet long. We invite you to learn more about this extraordinary object, its designer Charles Babbage and the team of people who undertook to build it. Discover the wonder of a future already passed. A sight no Victorian ever saw."

Online exhibit [Computer History]

Published by Rob Beschizza

Follow Rob @beschizza on Twitter.

Join the Conversation


  1. I agree, I’d love to see a proper video discussing and demonstrating the design and operation of this beast. In case you’ve ever wondered why we “crank out the numbers”…

    One of the problems with mechanical calculator was the frictional losses in those long gear chains. So a larger machine might need “torque amplifiers” between stages… and I can just see those being steam-powered…

    Or punk-powered if you prefer. “Don’t just sit there, you lazy sod; help crank the computer!” I can just see a team of computational bellows-pumpers…

  2. Oh, my god, this is a fantastic beast — WORKING! I was excited enough to see just part of an original Babbage machine — No. 1, Babbage’s original parts — in Sydney’s Powerhouse Museum a couple of years ago, but to see this — not original parts, but working, which the original never did — would blow my mind.

    This was a spectacular achievement, one of THE great intellectual achievements of all time, and there’s no better tribute than to MAKE one.

    I’m flabbergasted. Thank you.

  3. I stood and watched this fantastic beast being assembled in the Science Museum in London last summer. I could have watched all day, but there was much else to see. It’s very impressive up close.

  4. Call me when it’s powered by steam

    Babbage is famous for having said while correcting errors in astronomical tables, “I wish to God thes e calculations had been executed by steam.”

    According to Doron Swade, the senior curator at the Science Museum in London when the first machine was constructed, and head of that project, what Babbage meant wasn’t necessarily the literal use of steam power, but the general concept that properly designed mechanisms were more reliable than humans. Babbage’s design for the Difference Engine No. 2 shows the machine to be powered by a hand crank, though when constructed at the Science Musuem it was found necessary to add a 4:1 reduction gear as otherwise it required too much force for a person to crank it. Note that in the years since its construction the machine in London has been “broken in” and has become much easier to crank, suggesting that perhaps the 4:1 reduction could be removed.

    Had Babbage’s plans for the Analytical Engine come to fruition, it might very well have required actual steam power, as it had almost two orders of magnitude more moving parts than the Difference Engine No. 2.

    Why is there no link to the original article

    What original article would that be?
    The exhibit site is here.

    That one even prints out the answer on paper.

    So does this one, since they’re both the Babbage Engine No. 2.

    Printing on paper is one of the LEAST interesting thing the output mechanism does. It also produces stereotype plates for a printing press, and the formatting is programmable. It can format the results in two, three, or four columns, with adjustable line spacing, with an optional blank line every n rows, and in either row-major or column-major order.

  5. I wanted to hook up musical instruments to it and make clockwork techno. With magig lanterns for the lighting rig. Incidentally, an Italian contemporary of Babbage postulated doing almost exactly that.

Leave a comment

Your email address will not be published. Required fields are marked *