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slide rule

a device for performing mathematical calculations, consisting essentially of a ruler having a sliding piece moving along it, both marked with graduated, usually logarithmic, scales: now largely replaced by the electronic calculator.
1655-65 for earlier sense; 1875-80 for current sense Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for slide rule
  • After presiding over years of technological innovations, the inventor himself still prefers the simplicity of a slide rule.
  • Yet another familiar school-days object may be going the way of the inkwell and the slide rule.
  • Eventually, old fashioned books will go the way of the buggy whip and the slide rule.
  • The engineer is often not allowed sufficient time to perform long hydraulics formulas and exacting slide rule calculations.
  • Determine the relative humidity by reading the chart or slide rule provided with the psychrometer.
  • Most civil service written tests do not require the use of a calculator or slide rule.
  • Fortunately, wisdom has not gone the way of your slide rule.
  • Computations were performed by slide rule and, when luxury afforded it, a desk calculator.
British Dictionary definitions for slide rule

slide rule

noun (obsolete)
a mechanical calculating device consisting of two strips, one sliding along a central groove in the other, each strip graduated in two or more logarithmic scales of numbers, trigonometric functions, etc. It employs the same principles as logarithm tables
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Encyclopedia Article for slide rule

a device consisting of graduated scales capable of relative movement, by means of which simple calculations may be carried out mechanically. Typical slide rules contain scales for multiplying, dividing, and extracting square roots, and some also contain scales for calculating trigonometric functions and logarithms. The slide rule remained an essential tool in science and engineering and was widely used in business and industry until it was superseded by the portable electronic calculator late in the 20th century.

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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