EVER SINCE the Difference Engine No. 2 arrived at the Computer History Museum last May, I’ve been eager to see it for myself. After all, the thing is nearly unique — they call it “No. 2” because there are only two such contraptions in the world.
Designed in the 1840s by the English inventor Charles Babbage, the Difference Engine is essentially a mechanical computer, intended to crank out (and I mean literally crank out, with a crank) polynomial equations with superhuman accuracy. Imagining some fantastical gizmo out of a Jules Verne novel, I told Angela Hey, the Voice’s tech columnist, of my intention to see it.
“Well let’s set up a time,” she said. “I’ll get my husband to give us a tour.”
Hey’s husband is John Mashey, a trustee of the Computer History Museum and an enthusiastic booster and docent there. So a small group of us met at the museum last Friday, kicking off an amazing afternoon which started with the Difference Engine and ended, just as dazzlingly, with a tour by Mashey of the museum’s other exhibits.
The Difference Engine did not disappoint. It is beautiful to look at, and once set in motion, with its spinning hammers and cams, does indeed resemble some Victorian time machine. Curator David Varn gave a great presentation on it, explaining that Babbage never managed to build one himself, owing mainly to his “incontinent savagery,” i.e. poor people skills. But he got almost half-way to building one, an endeavor which Mashey called “The first well-funded computer startup failure.”
From there Mashey led us through the main museum, beginning with abacuses and ending with handhelds. The best way to experience this tour is with a docent, and it became clear that not only is Mashey intimately knowledgeable of computer history, he and Angela are actors in it, with personal contributions to, and relationships with, some of the field’s greatest companies and pioneers.
The museum is open Wednesdays through Sundays. Hours are 1 to 4 p.m. most days, 11 a.m. to 5 p.m. Saturdays. Live demonstrations of the Difference Engine are held regularly; visit www.computerhistory.org/hours.
Don Frances can be reached at dfrances@mv-voice.com.
