Webster's Revised Unabridged Dictionary · 1913

(Physics) A unit of work which is equal to 107 ergs (the unit of work in the C. G. S. system of units), and is equivalent to one watt-second, the energy expended in one second by an electric current of one ampere in a resistance of one ohm; also called the absolute joule. It is abbreviated J or j. The international joule is slightly larger, being 1.000167 times the absolute joule. The absolute joule is approximately equal to 0.737562 foot pounds, 0.239006 gram-calories (small calories), and 3.72506 x 10-7 horsepower-hours, and 0.000948451 B.t.u. — HCP61