In this Sense Livy, describing the Luxury into which the Romans degenerated after the Conquest of Asia, says, They had their Abaci, Beds, &c. plated over with Gold. Dec. IV. Lib. ix.

The Word is Latin, but form'd from the Greek,

Abacus was particularly us'd among the Mathematicians, for a little Table strew'd o'er with Dust, on which they drew their Schemes and Figures. And hence the Abacus Pythagoricus, a Table of Numbers, contriv'dsor the ready learning of the Principles of Arithmetic ; denominated from its Inventor Pythagoras.

Hence also, from an Agreement in point of Use, the Karnes Abacus and Abaco, are us'd among the English and Italians for an Alphabet, or A B C, &c.

The Abacus Pythagoricus was, in all probability, no other than what we call Multiplication-Table. See TABLE.

Ludolsus and Wulsius give us Methods of performing Multiplication without the help of the Abacus; but they are too operose in ordinary Cases for Practice. See MULTIPLICATION.