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 ...
Microfiche. Washington, D.C. : Smithsonian Institution Libraries, 1994. 3 microfiches ; 11 x 15 cm. Negative held by Preservation Services.
This compact cylindrical handheld calculating machine has black metal sides and a plastic top and operating handle. Eight slots along the side of the cylinder hold levers that are pulled down to set ...
Some results have been hidden because they may be inaccessible to you
Show inaccessible results
Feedback