This key-set, non-printing stepped drum calculating machine has a metal case painted black. Each of the nine columns of keys has nine black plastic keys. Between each row of keys, rods that are black ...

IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. In 1895, Otto Steiger, a Swiss ...

THE first calculating machine was invented in 1642 by Blaise Pascal. Had it not been for the War, the tercentenary of this event, which has had such a profound influence on applied mathematics and ...