Difference Engines out of Toys? Posted on February 9th, 2006 by

As you may or may not know, one of the first calculators (abacus excluded) was a giant gear-laden monstrosity conceived of computing pioneer Charles Babbage back in the early 1800’s. His “difference engine” used gears to calculate 7th order polynomials to 31 digits of accuracy.

here are a few modern attempts at using his logic to create simpler difference engines out of toys:

This difference engine is made of legos. Speaking of computing pioneers, you may recognize the name of the guy providing the web hosting for this site — one Steve Wozniak (who worked on the original Apple computers).

This difference engine is made of Meccano (similar to Erector set)



  1. max says:

    Thanks for the interesting links, Matt. I like to bring Babbage’s difference engines up in my compiler design class, because the principle of differences on which those engines were based is the exact same principle that is used for “strength reduction optimization” in modern compilers. (Another important lesson from Babbage is that communication skills and the management of interpersonal relationships matter greatly. Many historians think one important factor in his failure to bring his visionary designs to fruition was his limitations in these areas.)

  2. mweier says:

    as long as we’re rambling about babbage, I may as well throw this into the meme pool…

    William Gibson and Bruce Sterling have written a piece of historical fiction about the difference engine, name, perhaps appropriately, The Difference Engine. It’s a far cry from Gibson’s other cyberpunk works — this one is an alternate history written in the genre that has been dubbed steampunk for its historical take on sci fi. It may be interesting to people who want to read more on the period as it never happened, and in novel form. While looking for the link to the book, I stumbled across this online encyclopedia concerned entirely with The Difference Engine.

  3. Brad Richards says:

    For those with an interest in things Babbage, Flare Productions did an hour-long documentary on Ada Lovelace in 2003 called “To Dream Tomorrow. I really enjoyed it, and a highlight was seeing a replica difference engine cranking away (briefly). You can buy a copy at http://www.mith.umd.edu/flare/.

  4. Farank says:

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