unit, unite

[An abbrev. of unity (q. v.).] I. Ord. Lang.: A single person or thing regarded as having onene for its main attribute; a single culationn one of a number, forming the basis of count or cal II. Technically : 1. Arith .: 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. 2. Math . & 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. 1. 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 sys tem of natural numbers, and incidentally the base of all quantities. 2. Decimal and duodecimal units : Those in scales of numbers increasing or decreasing by ten or IMG:content-0164.png:[blocks in formation] 4. Electric units: (1) Unit of quantity : A coulomb. The quantity of electricity that will liberate.000162 grains of hydrogen from water, or '005232 grains of zinc from a solution of the metal. In this unit, rate or time is taken no account of. (2) Unit of current : An ampere; a current flowing at the rate of one coulomb per second, or liber ating 000162 grains of hydrogen, ., per second. (3) Unit of electro-motive force : A volt (q. v.). The force or difference of potential required to produce, through a wire of one ohm resistance, a cur rent of one ampere. (4) Unit of resistance : The legal unit of resist ance, as settled by the International Electrical Congre , at Paris, 1884, is that of a column of pure mercury 106 centimeters long, 1 square millimeter in sectional area at 0°C. The name ohm is now confined to this unit, but was formerly used to denote an older unit chosen by the British A ocia tion, which is to the legal ohm as 1.0112 to 1. (5) Unit of capacity : A farad (q.v.). A condenser has a capacity of one farad when a potential difference of one volt between its two sets of plates charges each of them with one coulomb. (6) Absolute units : The absolute electro-motive force unit is a force, and the absolute unit mag netic pole is a pole, which, when placed at a distance of one centimeter, from a similar force or pole, repels it with a force of one dyne. These units are inconveniently small for actual use, thus one volt 108 absolute units. (7) Unit of work done : The watt (q. v.); the rate at which electrical work is done is measured by watts. A watt is the power developed in the cir cuit, when one ampere of current produces one volt difference of potential at the terminals. Hence this electrical result=one 746th part of one horse-power. [3 (2).] 5. Fractional unit : The unit of a fraction. Thus in the fraction there is an a emblage of three units, each of which is one-fourth of the whole numbar. 6. Integral unit : The unit 1; the unit of integral numbers. 7. 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 8. Unit of heat : [THERMAL-UNIT.] 9. 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. 10. Unit of measure : The unit of measure of any the quantity is compared. quantity is a quantity of the same kind, with which 11. Unit of value : In England, a pound sterling, represented by a gold coin called a sovereign (q. v.). In the United States, a gold dollar, weighing 25.8 grains, one-tenth of which is alloy.