History of the Curta Calculator
The Curta calculator is the only mechanical, digital pocket calculator ever invented. It was invented by Curt Herzstark. Curt conceived the idea in the 1930s, patented it and had began work on its design. However since he was half-Jewish and lived in Austria, he was arrested and taken to Buchenwald concentration camp in 1943.
Surprisingly the Nazis there encouraged him to continue his work, hoping to eventually present his calculator to Adolf Hitler as a congratulatory gift after he won the war. Their plans were never realized but Hertzarks’ plan came to fruition towards the end of 1945. He found skilled machinists in a factory in Weimar. With their help he came up with three prototypes.
Engineer Herzstark eventually fled to Austria where he continued working on the Curta calculator while looking for financial sponsors. Among his sponsors included the Prince of Lichtenstein. Together they formed a company Contina AG Mauren and production of the Curta Type 1 began in Liechtenstein.
His sponsors tried to screw him by taking over control of production and keeping all the profits for themselves, but luckily Herzstark had patented his work and the financial backers were forced to negotiate a favorable deal with him.
There were two types of Curtas: Type 1 and Type 2.
Where can I get one?
The Type I Curta has eight digits for data entry (known as “setting sliders”), a six-digit revolution counter, and an eleven-digit result counter. According to the advertising literature, it weighs only 8 ounces (230 g).
The larger Type II Curta, introduced in 1954, has eleven digits for data entry, an eight-digit revolution counter, and a fifteen-digit result counter. It weighs 13.15 ounces (373 g).
The Curta calculators continued to enjoy their popularity until they were displaced by electronic calculators in the 1970s. According to Curt Herzstark, the last Curta was produced in 1972.
As of Jun 2016, a Type 1 can be found on ebay starting at about 600$ while a Type 2 can be found from about $800.