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 ...

In the early days of aviation, pilots or their navigators used a plethora of tools to solve common navigation and piloting ...

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 ...

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 ...

For about 350 years, humanity’s most innovative handheld computer was something called a slide rule. As typewriters once symbolized the writer, slide rules symbolized the engineer. These analog ...