Lógarithms. n.s. [logarithme, Fr. λόγος and ἄριθμος.]
Logarithms, which are the indexes of the ratio's of numbers one to another; were first invented by Napier lord Merchison, a Scottish baron, and afterwards completed by Mr. Briggs, Savilian professor at Oxford. They are a series of artificial numbers, contrived for the expedition of calculation, and proceeding in an arithmetical proportion, as the numbers they answer to do in a geometrical one: for instance,
Where the numbers above, beginning with (0), and arithmetically proportional, are called logarithms. The addition and subtraction of logarithms answers to the multiplication and division of the numbers they correspond with; and this saves an infinite deal of trouble. In like manner will the extraction of roots be performed, by dissecting the logarithms of any numbers for the square root, and trisecting them for the cube, and so on. Harris.