CONSONANCE

, in Music, is commonly used in the same sense with concord, viz, for the union or agreement of two sounds produced at the same time, the one grave, the other acute, which is compounded together by such a proportion of each, as proves agreeable to the ear.

An unison is the first consonance, an eighth is the 2d, a fifth is the 3d; and then follow the fourth, with the third and sixths, major and minor.

CONSTANT Quantities are such as remain invariably the same, while others increase or decrease. Thus, the diameter of a circle is a constant quantity; for it remains the same while the abscisses and ordinates, or the sines, tangents, &c, are variable.

These are sometimes called given, or invariable or per- manent quantities; and in algebra it is now usual to represent them by the leading letters of the alphabet, a, b, c, &c; while the variable ones are denoted by the last latters, z, y, x, &c.