The difference engine was nearly ready for Babbage’s birthday celebration, but the project ran out of money before completion of the machine’s typeset and print functions. When Microsoft’s Bill Gates saw the work in progress, he suggested that Myhrvold, who's an inventor, archaeologist and investor, might finance the completion of it. Only if the London Museum agreed to build a working replica for his private collection, Myhrvold said in sealing the deal. After the colossal calculator leaves the Silicon Valley museum, it’s bound for Myhrvold’s home in Seattle, perhaps joining the Tyrannosaurus rex skeleton in his living room.
Meanwhile, the machine is demonstrated Wednesday through Friday at 2 p.m. and on weekends at 1 and 2 p.m. During a recent visit, a docent turned the crank of the foot-wide wheel, putting her back into it. As the gears and cams clicked into motion, one onlooker remarked that the movement looked like the double helix of DNA. The audience seemed mesmerized by the calculator’s elegant precision. At long last, Babbage’s genius was getting its due.