The Curta Pocket Calculator

"It is a precision instrument, performing calculations mechanically, employing neither electricity nor electronic components. The sensation of its operation is best likened to that of winding a fine thirty-five-millimeter camera. It is the smallest mechanical calculating machine ever constructed.

"It is the invention of Curt Herzstark, an Austrian, who developed it while a prisoner in Buchenwald. The camp authorities actually encouraged his work, you see. 'Intelligence slave,' his title there. They wished his calculator to be given to the Führer, at the end of the war. But Buchenwald was liberated in 1945 by the Americans. Herzstark had survived."

That was a monologue from a character out of William Gibson's excellent 2003 novel Pattern Recognition about the object pictured above.

The first time I read the book, two years ago, I assumed that the Curta was an invention of the author. When I re-read it this summer, I noticed in the acknowledgements that Gibson thanks a James Dowling "for introducing me to the Curta calculator."

It is a real thing. There's a good description of its operation at the Museum of HP Calculators website. And there's a website that simulates the Curta's operation if that doesn't make sense.

When Curt Herzstark got out of the concentration camp, he arranged to have his invention produced. The Curta was made from 1948 to 1972, the year that electronic pocket calculators got cheap enough to put the mechanical calculator out of business. They seem to be going for between $600 and $1,200 on eBay right now.