"A representation of a common form of the delicate balances employed in physical and chemical researches. the beam is constructed so as to combine lightness with strength, and rests by a fine knife-edge on an agate plane. It is surmounted by a weight moving on a screw, so that the sensibility may be increased or diminished, according as weight is raised or depressed." — Chambers' Encyclopedia, 1875

Balance

"A representation of a common form of the delicate balances employed in physical and chemical researches.…

The Library of Congress is the de facto national library of the United States and the research arm of the United States Congress.

The Congressional Library

The Library of Congress is the de facto national library of the United States and the research arm of…

"The Steelyard is more portable then the ordinary balance. It consists of a lever, AB, moving round a knife-edge or point at C. The body to be weighed, W, is put into the scale which hangs from A; and a movable weight P, is made to slide along the longer arm, until the lever, AB, remains horizontal." — Chambers' Encyclopedia, 1875

Steelyard

"The Steelyard is more portable then the ordinary balance. It consists of a lever, AB, moving round…