1. A measure; a standard of measure; an instrument to determine dimensions, distance, or capacity; a standard. This plate must be a gauge to file your worm and groove to equal breadth by. (Moxon) There is not in our hands any fixed gauge of minds. (i. Taylor)
3. (Science: machinery) Any instrument for ascertaining or regulating the dimensions or forms of things; a templet or template; as, a button maker's gauge. To measure the dimensions of, or to test the accuracy of the form of, as of a part of a gunlock. The vanes nicely gauged on each side. (Derham)
4. (Science: physics) Any instrument or apparatus for measuring the state of a phenomenon, or for ascertaining its numerical elements at any moment; usually applied to some particular instrument; as, a rain gauge; a steam gauge.
5. Relative positions of two or more vessels with reference to the wind; as, a vessel has the weather gauge of another when on the windward side of it, and the lee gauge when on the lee side of it. The depth to which a vessel sinks in the water.
6. The distance between the rails of a railway. The standard gauge of railroads in most countries is four feet, eight and one half inches. Wide, or broad, gauge, in the united states, is six feet; in England, seven feet, and generally any gauge exceeding standard gauge. Any gauge less than standard gauge is now called narrow gauge. It varies from two feet to three feet six inches.
gauge of a carriage, car, etc, the distance between the wheels; ordinarily called the track. Gauge cock, a stop cock used as a try cock for ascertaining the height of the water level in a steam boiler. Gauge concussion, an instrument for measuring the diameter of the bore of a cannon at any point of its length. Steam gauge, an instrument for measuring the pressure of steam, as in a boiler. Tide gauge, an instrument for determining the height of the tides. Vacuum gauge, a species of barometer for determining the relative elasticities of the vapor in the condenser of a steam engine and the air. Water gauge. A contrivance for indicating the height of a water surface, as in a steam boiler; as by a gauge cock or glass. The height of the water in the boiler. Wind gauge, an instrument for measuring the force of the wind on any given surface; an anemometer. Wire gauge, a gauge for determining the diameter of wire or the thickness of sheet metal; also, a standard of size.
Origin: Written also gage.