Most early calculating machines carried out multiplication as a form of repeated addition. To multiply, say, by thirteen, one set the carriage at its rightmost position, turned the operating crank ...

Invented by Leonardo Torres in 1920, the Torres calculating machine is a machine that solves essential addition, subtraction, multiplication, and division problems using a simple manner. It was a ...

IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. This lightweight modified stepped ...