Stanford University is hosting an exhibit on the 350 year history of that hoary tool of the engineering world: the slide rule.
The slide rule was the most convenient calculator available to builders and scientists until the development of electronic calculators a few years ago. They also made great looking tie clips.
Scottish theologian John Napier laid the foundation for the invention of the slide rule in 1614 with the invention of logarithms. In 1622, the mathematician William Oughtred set two straight edges marked with logarithmic scales side by side and created the first rectilinear slide rule.
The exhibit was put together by petroleum engineer Tom Wyman and Robert Otnes, an engineer specializing in communication theory, both of whom collect them. Among other items, the exhibit includes a silver and ivory rule made in London around 1860. Wyman is also president of the Oughtred Society, a group dedicated to the history and preservation of the slide rule and other mechanical calculators.
The Rise and Fall of the Slide Rule: 350 Years of Mathematical Calculators is being held in the university's Green library through October 9.