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  1. Oh… I didn’t mention in all my babbling, that those are really excellent pictures of the Engine, Collie!

    They’re also good pictures of the crowd of happy geeks.

    I wonder if we had gone a different day if the Difference Engine would have been nearly as impressive?

    I mean sure, it’s a cool display standing there all by itself, even cooler when the docent cranked it about, and it whirred and clunked and moved with all it’s mechanical grace…

    … but to see it there, surrounded by people who have come to gape and admire, and listen to the stories of the frustration and the politics of both Mr. Babbage and Dr. Swade… that was so much more powerful than just seeing a big box of gears sitting there.

    I, too noticed the geeks with their iphones and multi-gigabyte digital cameras and pocket Internet connections. Heck, I was one of them. It was hard not to contrast a five ton calculator with having the Internet available on my cellular phone.

  2. What an excellent write-up of a beautiful and fascinating day.

    I found Dr. Swade to be a fascinating and engaging speaker, and was very glad to have gone up and seen him. He had a lot of details of both the story of the Difference Engine, and the construction of the engines they built that were wonderful, and I stood there and listened to him all afternoon.

    The Engine itself is also quite impressive. Your description, “Standing there in person, watching the levers and wheels and numbers and cogs all dancing perfectly interlinked, is like watching visual mathematical prose.” is wonderful. Imagine how someone in the Victorian era, lacking all of our modern advances would see it. They called it a “Thinking Machine” and it must truly have seemed that way to them.

    I remember a couple of details differently than you do, particularly around the origin of the printer, and about the Analytical Engine.

    The plans for the original Difference Engine did not include any kind of printer. Output was by reading numbers printed on the gear wheels themselves. This left an opening for transcription and typography errors.

    A competitor produced an inferior mechanism – less accurate, possible to run with errors, etc. – but it included a printer.

    While this went on Babbage was designing the Analytical Engine. One thing you missed in describing it is that it is not just a calculator but what we would call a fully programmable computer. It was programmed via punched cards, and had variables, looping, and storage. It would have been a steel, bronze, and wood contraption comparable to the first microprocessors or the giant relay-based systems.

    The printer was designed for the Analytical Engine, to give it the ability to produce pages that could be printed off as books, eliminating the typographical and transcription errors.

    After designing the Analytical Engine, Babbage realized his Difference Engine could be built more simply. The Difference Engine No. 2 we saw was his second design for the Difference Engine. It was, if you can imagine it, much simpler than the first design!

    Since he had a design for a printer which did all these wonderful things, he simply used it on the new design for the Difference Engine No 2. Dr. Swade says it uses the same mechanical connections and should just bolt on.

    Dr. Swade says they made many small design changes to facilitate building the machine, all things that Babbage himself might have made. The only changes they made were not the springs, but many things like that to aid in building and operating the machine. They did not add the printer; Babbage used it himself in the design of Difference Engine No. 2.

    I also asked the docent why the printer was not printing. The Difference Engine we saw had only been in operation a few hours. The printer and stereography (is that the right word?) section weren’t set up yet. The samples in the display case were made on the Difference Engine No. 2 in London, which has been working for a year. They will probably ink this one up after they have it working smoothly.

    Apparently shipping it by air was hard on the machine, and it was coming apart and completely misaligned. They were working on getting it running steadily, and were pleased that it would work at all when we saw it.

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