Curta calculator

The Curta calculator emerged because three centuries of mechanical calculation had converged into a design problem that only extreme miniaturization could solve—and the solution came from a man who perfected it while imprisoned in a Nazi concentration camp as a gift intended for Adolf Hitler.

Curt Herzstark (1902-1988) grew up surrounded by calculating machines. His father Samuel Jacob Herzstark had manufactured the Austria calculator in Vienna since 1905. By the 1930s, Curt envisioned something revolutionary: a handheld calculator using a complemented stepped drum that could perform addition, subtraction, multiplication, and division. He filed a key patent in 1938, but history intervened.

In 1943, two of Herzstark's employees were discovered transcribing BBC broadcasts. At least one was executed; Herzstark was arrested for 'helping Jews and subversive elements' and sent to Buchenwald concentration camp. But the SS knew of his calculator design. They wanted him to complete it as a victory gift for the Fuhrer. This macabre commission saved his life.

Classified as an 'intelligence slave,' Herzstark worked in the secret Gustloff factory adjoining the camp. He used his position to save other prisoners by creating jobs for them. His calculator design crystallized in these brutal conditions, the extreme constraints of hand-held operation forcing elegant solutions to centuries-old mechanical problems.

U.S. troops liberated Buchenwald on April 11, 1945. By November, Herzstark had produced three working prototypes at a factory near Weimar. Fearing Soviet deportation of skilled workers, he dismantled the machines, disguised them as children's toys, and smuggled them to Switzerland. After failed negotiations with several companies, Prince Franz Joseph II of Liechtenstein—eager to modernize his principality—backed production.

Mass manufacturing began in 1948 in Mauren and Eschen. The result earned nicknames: 'pepper grinder' for its shape, 'math grenade' for its resemblance to hand grenades. Between 1948 and 1972, 140,000 Curtas were manufactured. They remained the best portable calculators available until electronic calculators displaced them in the 1970s.

The Curta represents the culmination of mechanical calculation that began with Schickard, Pascal, and Leibniz in the 17th century. It was perfected not despite the concentration camp, but partly because of it—the extreme constraints forcing Herzstark toward solutions he might never have reached in peacetime comfort. After liberation, he received the Order of the Luxembourg Brotherhood for rescuing a Luxembourg worker during his imprisonment.