The Curta Peppergrinder

I hate to admit it, but I came of age in the era of the slide rule. To be more precise, I had a Post Versalog that I proudly used throughout my undergraduate engineering days at the University of Michigan. No, I did not hang it on my belt nor did I have a pocket protector for my pens. Slide rules were just the tools of the trade if you were in a computationally-intensive academic discipline. I still have my slide rule in a box somewhere in the basement.

Just after I entered grad school in 1974, electronic calculators made their debut. HP lead the way but they were expensive and a lot of engineers didn't like the RPN (Reverse Polish Notation) method of computing. I had a Texas Instruments SR-51 programmable calculator. I still have that, too.  Why? I knew that they would eventually become iconic symbols of a computing past that was rapidly evolving.

It surprised me to learn recently of an even earlier iconic mechanical calculator called a Curta. I had never heard of it or even seen a picture of one but a little digging on the internet last night brought a wealth of information about this little marvel.

The Curta was developed in Europe around the time of World War II by an engineer named Curt Herzstark. Herzstark was born in 1902 and had a natural aptitude for engineering. Herzstark's father owned a mechanical calculator company in Vienna before the war and Curt worked for the company. When the Nazis occupied Austria in 1938 under the so-called Anschluss, the factory was converted to making military supplies. Still, things remained relatively stable until 1943 when the war started going very badly for the Nazis on many fronts. Curt Herztark was arrested for being sympathetic to Jews (he was half-Jewish himself even though he was raised as a Christian). He eventually was sent to the notorious Buchenwald concentration camp near Weimar, Germany. He was assigned to work as a slave laborer in an adjacent factory. His engineering talents were recognized and he was put to work in the office doing design work. While there, he told the factory supervisors of patents he had been awarded in 1938 for a miniature hand-cranked mechanical calculator that could perform the four basic math functions very efficiently.  Intrigued, his supervisors set him to work to perfect his design. The camp commandant planned to give one to Hitler as a gift of appreciation after Germany won the war.

Herzstark set to work immediately and produced a complete set of working drawings by the time Buchenwald was liberated by the Allies on April 11, 1945. With the Soviets  on the verge of occupying that part of Germany, Herzstark fled to Austria. He immediately began to seek funding to build his design. Eventually, he found support from the Prince of Liechtenstein who was trying to establish a post-war manufacturing base in his tiny country.

Curt Herzstark produced his namesake calculator (Curta means offspring of Curt) from 1947 to 1970 when, like the slide rule, mechanical devices gave way to electronic calculators. The Curta was nicknamed the Pepper-mill for its obvious resemblance to that culinary device.

Curta's were expensive ($125 to $175) but very compact and highly accurate. Their size made them popular with airplane pilots and rally race car navigators. Over 140,000 of the devices were made during their heyday. You can still find them on eBay for prices in the one to five thousand dollar range.

Curt Herzstark died on October 27, 1988 in Vienna. He had lived through some of the worst of times to see his ideas validated and embraced by a world rapidly moving forward towards high-speed computation. If I were ever so lucky as to find one of these little beauties for a reasonable price, it would join my Post Versalog and SR-51 as a reminder of what came before.