Unit

Collier's New Encyclopedia (1921)

in arithmetic, the least whole number or one, represented by the figure 1. Numbers are collections of things of the same kind, each of which is a unit of the collection . Thus 20 feet is a collection of 20 equal spaces, each of which is equal to 1 foot ; here 1 foot is the unit or base of the collection. In mathematics or physics, any known determinate quantity by the constant repetition of which any other quantity of the same kind is measured . It may be a length, a surface, a solid, a weight, a time, as the case may be. Abstract unit, the unit of numeration ; the abstract unit 1 is the measure of the relation of equality of two numbers. It is the base of the system of natural numbers, and incidentally the base of all quantities. Decimal and duodecimal units, those in scales of numbers increasing or decreasing by 10 or 12 respectively. Dynamic units: Unit of force, a dyne; a force which, acting for one second on a mass of one gramme, gives to it a velocity of one centimeter per second. Unit of work done, a watt; the power developed when 44.25 foot pounds are done per minute=one 746th part of a horsepower. Fractional unit, the unit of a fraction . Thus in the fraction there is an assemblage of three units, each of which is one-fourth of the whole number. Integral unit, the unit 1; the unit of integral numbers. Specific gravity unit, for solids or liquids, one cubic foot of distilled water at 62° F.=1; of air and gases, one cubic foot of atmospheric air at 62°. Unit of illumination, the light of a sperm candle burning 120 grains per hour. The standard for gas is that the flame, burning at the rate of five cubic feet per hour, shall give a light equal to the light of 14 sperm candles, each consuming at the rate of 120 grains per hour. Unit of measure, the unit of measure of any quantity is a quantity of the same kind, with which the quantity is compared. Unit of value, in England , a pound sterling, represented by a gold coin called a sovereign. In the United a gold dollar , weighing 25.8 grains, onetenth of which is alloy. pound ited States,