This circular slide rule consists of a silver-colored metal dial, 8-1/2" wide, mounted on a silver-colored metal disc. Three oblong holes on the base disc permit the reading of trigonometric scales on ...

IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. Leather belting produced from cowhide ...

While some (math-phobics) still may relish the simple beauty and non-threatening functionality of the abacus, there are those who have made the transition to more challenging computing gadgets—many ...

An early computing device invented by Reverend William Oughtred in London in the 17th century. Primarily for multiplication and division, the slide rule has two stationary sets and one sliding set of ...

In the grand scheme of things, it really wasn’t all that long ago that a slide rule was part of an engineer’s every day equipment. Long before electronic calculators came along, a couple of sticks of ...

Used by engineers for centuries, they were displaced by pocket calculators and all but forgotten until Mr. Shawlee created a subculture of obsessives and cornered the market. By Alex Traub For about ...