among the ancients, was a kind of cupboard or buffet. 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.

among the ancient mathematicians, signified a table covered with dust, on which they drew their diagrams; the word in this sense being derived from the Phoenician abak, dust.

or ABACISCUS, in Architecture, signifies the superior part or member of the capital of a column, and serves as a kind of crowning to both. Vitruvius tells us the abacus was originally intended to represent a square tile laid over an urn, or rather over a basket.

See Architecture, No. 15.—The form of the abacus is not the same in all orders: In the Tuscan, Doric, and Ionic, it is generally square; but in the Corinthian and Composite, its four sides are arched inwards, and embellished in the middle with some ornament, as a rose or other flower. Scamozzi uses abacus for a concave moulding on the capital of the Tuscan pedestal; and Palladio calls the plinth above the echinus, or boutin, in the Tuscan and Doric orders, by the same name.

ABACUS is also the name of an ancient instrument for facilitating operations in arithmetic. It is variously contrived. That chiefly used in Europe is made by drawing any number of parallel lines at the distance of two diameters of one of the counters used in the calculation. A counter placed on the lowest line, signifies 1; on the second, 10; on the third, 100; on the fourth, 1000, &c. In the intermediate spaces, the same counters are eliminated at one half of the value of the line immediately superior, viz. between the first and second, 5; between the second and third, 50, &c. See Plate I., fig. 1, where the same number, 1820 for example, is represented under both divisions by different positions of the counters. A farther illustration of this mode of notation is given in fig. 2.

National debt, according to Mr Addington, 1st Feb. 1804,

| According to Mr Tierney | L. 400,709,832 | |-------------------------|----------------| | According to Mr Morgan | 457,154,681 | | New finking fund | 538,418,628 | | Old finking fund | 3,275,143 | | | 2,534,187 |