This full-keyboard, electric non-printing pinwheel calculating machine has eight columns of black and white color-coded plastic keys, with a red clearance key at the bottom of each column. The ...
Anyone who is baffled by mathematics beyond the multiplication tables can imagine with awe the Brobdingnagian mental efforts involved in inventing a clerkproof, 5,500-part machine that adds, subtracts ...
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 lever-set, non-printing, and ...
Some results have been hidden because they may be inaccessible to you
Show inaccessible results
Feedback