Eldon Street, Sheffield.
_Notation by Coalwhippers_ (Vol. iv., p. 21.).--The notation used by
coalwhippers, &c., mentioned by I. J. C., is, after all, I expect, but a
part of a system which was probably the origin of the Roman notation.
The first four strokes or units were cut diagonally by the fifth, and
taking the first and last of these strokes we readily obtain V, or the
Roman five; but as the natural systems of arithmetic are decimal, from
the number of fingers, it is most probable that the _tens_ were thus
marked off, or by a stroke drawn across the last unit thus X, whence we
obtain the Roman ten: these tens were repeated up to a hundred, or the
second class of tens, which were probably connected by two parallel
lines top and bottom [C], which would be the sign of the second class of
tens, or hundreds; this became afterwards rounded into C: the third
class of tens, or thousands, was represented by four strokes M, and
these symbols served by abbreviation for some intermediate numbers; thus
X divided became V, or 5, the half of 10; then L, half of [C],
represented 50, half of 100; and M becoming rounded thus (M) was
frequently expressed in this manner CI*C; and this became abbreviated
into D, 500, half of CI*C; or 1000: and thus, by variously combining
these six symbols (though all derived from the one straight stroke),
numbers to a very high amount could be expressed.