Bunzel-Delton Calculator
Bunzel-Delton Calculator
The arithmometer, invented by Charles Xavier Thomas de Colmar in 1820, was the first commercially successful calculating machine capable of performing addition, subtraction, multiplication and division. The Thomas Arithmometers were produced and sold in Europe and the United States well into the 20th century, and were widely imitated and marketed by many manufacturers, such as this 1908 Bunzel-Delton machine from Austria.