Curtas were the greatest portable calculators obtainable until electronic calculators replaced them in the 1970s. A total of 140,000 Curta calculators were produced (80,000 Type I and 60,000 Type II).
– Due to its design and mode of operation were dubbed the “pepper grinder” or “peppermill.”– Its apparent similarity to a particular hand grenade gained it the title “math grenade.”
Curt Herzstark’s Curta is a unique mechanical calculator developed on Lebnitz’s stepped drum mechanism. This single drum replaced the many drums seen in conventional calculators, which often number tens.
The fundamental design is a pepper-pot-shaped metal barrel with a winding handle at the top and a ring pull next to it. To perform the computations, spin the handle, or crank, clockwise.
The Curta proved to be a far more unique creation than the considerably larger calculating machines available at the time. Curtas were extremely practical and helpful instruments widely used, particularly in the surveying and engineering industries.