ABACUS.-. An instrument employed by the ancients for facilitating
calculations ; similar to that now frequently employed for teaching
children the rudiments of arithmetic, and which is commonly sold in our
stationers' shops, It usually consists of twelve parallel wires, fixed in a light
rectangular frame; each wire carrying 12 beads or balls. There are thus
12 times 12, answering to the common multiplication-table, all the
results of which it demonstrates to the dullest capacity. All the operations of
addition or subtraction likewise performed by it, by merely moving the beads
from one side to the other of the frame. By thus smoothing
the difficulties of acquiring arithmetical knowledge at the very outset, and
rendering it quite obvious and amusing at the same time, the apparatus becomes
one of considerable importance in education.
Another kind of abacus consists of a series of parallel wires fixed in a frame like
the former., On each wire there are nine little balls; the lowest
stand for units, the next above for tens, the next
hundreds, and so on up to any number. The frame is divided into two
compartments, a and b, by a cross-wire at c,
which is sufficiently raised above the wires to allow the little balls to
slide under it. Suppose the whole 63 balls to be placed in the compartment
a, and it be proposed to note the sum of 4,346,072, it is effected by
sliding, the balls shown in b from their previous situation in a. See CALCULATING-MACHINES .
Your Comments Welcomed! Copyright © 1995 Roger Corrie