Contina Curta Type II

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Contina Curta Type II

Type: Mechanical Calculator
Size: 2.5 inches diameter x 4.5 inches / 6.5 cm diameter x 11 cm
Material: Steel

The Curtas have been called the first and last handheld mechanical calculators. Before you say, "What about the Addiator?" you should note that the Curtas can do multiplication and division as well as addition and subtraction. For multiplication and division, one turns a cylinder that defines which place in the number you're operating on. Essentially, one does multiplication by repeated addition, but staggered from place to place. Think about how you did long multiplication in grammar school and you'll begin to understand the method. Division was done the same way, via staggered repeated subtraction.

The calculator was invented by Curt Herzstark, the son of an Austrian adding machine maker. Though not Jewish, he spent some time in concentration camps for defending others. While there, he had some free time to think about the way calculators can be built, and hit upon the cylindrical idea you see in the photos. After the war Herzstark finished up the development of his invention and opened a small factory in Liechtenstein. Curta calculators were manufactured from 1947 to 1970. The current unit dates from around February of 1957.

Curta calculators were a favorite of road rally teams in the 50s and 60s, being small enough for a skilled navigator to work with one hand while computing course corrections.

See Rick Furr's excellent Curta website at http://www.vcalc.net/cu.htm.