“Math Grenade” – The Curta Mechanical Calculator
This elegant, palm-sized device that sold at a past Beehive has several cute nicknames, including “the pepper grinder” and “the math grenade”. It is properly called “the Curta”, after its Austrian inventor, Curt Herzstark. An early calculator, the Curta is completely mechanical – no batteries, no silicon chips! It is operated entirely by turning, cranking and sliding its various interlocking parts. And, it is accurate. Unlike the calculator app on your phone, there is a bit of a learning curve to using a Curta and they came with lengthy instruction pamphlets.
There were two versions made – the Type I and the Type II. You can tell a Curta was an expensive purchase since it came packed inside TWO protective cases, an inner metal canister and an outer leather carrying case.
Curt Herzstark filed his first patent for the Curta’s inner workings in 1938 and had prototypes manufactured in 1945. The Curta is not the first mechanical calculator, earlier versions by multiple inventors built on ideas going back hundreds, even thousands of years, and from disparate sources. Mariners’ navigational astrolabes, mechanical, pattern- weaving Jacquard textile looms, and a much simpler mechanical calculator, the slide rule, (which predates the Curta by around 300 years) all contributed crucial concepts.
But the Curta was considered one of the finest calculators of its time, both for its reliability and its compact design. Around 140,000 Curta calculators were made (80,000 Type I, 60,000 Type II). The Curta met its commercial demise in the 1970s, displaced by Hewlett Packard and the first hand-held electronic calculators that hit the market. The last Curta left the factory in 1972.
|But that was not the end! The Curta continued to be used by rally racecar drivers well into the 1980s because they needed to do accurate TSD (time-speed-distance) computations while driving and early electronic calculators were too delicate to function in a hurtling, bouncing race car. And it is worth mentioning that there are still thousands of functional Curtas with us. Prized by collectors, they can sell for up to $2,000, which would probably be gratifying to their inventor, Curt Herzstark, who went through a lot for his elegant device.
The reason there are 7 years between patent application and first prototype is Herzstark was the son of a Catholic mother and Jewish father living in Vienna in 1938 under Nazi rule. At first they forced his small company to make other precision instruments for the German military, but compliance did not protect him and in 1943 he was sent to Buchenwald concentration camp, probably to die. In his own words “The head (…) said, ‘I understand you’ve been working on a new thing, a small calculating machine. (…) If it is really worth something, then we will give it to the Führer as a present after we win the war. Then, surely, you will be made an Aryan.’ For me, that was the first time I thought to myself, my God, if you do this, you can extend your life.” Liberated by U.S. troops in 1945, Herzstark found a factory in Sommertal that could produce working Curta prototypes but then had to flee to Austria as the Soviet army invaded. It took the interest of the Prince of Liechtenstein to finally get manufacturing of the Curta up and running.
But, before all that comes this adorable 1910 photo of young Curt at an office equipment exhibition in Vienna. Aww! We at QBO are glad this life-long love affair has a happy ending.