eyboard. This frame is mounted
horizontally on a slide, which by an ingenious mechanical movement
brings any one of the two hundred and twenty-five matrices over what
is termed the mould. The particular matrix thus placed in position is
determined by those particular holes punched in the paper ribbon at
the keyboard, through which the compressed air is at that precise
moment being forced.

The mould referred to is closed by the matrix, a jet of molten metal
is forced in, and in an instant the type is cast, its face being
formed by the matrix, its body or shank by the mould. The cast type is
ejected and takes its place in the galley, to be followed by another
and that by yet others in their regular rotation. It must, however, be
pointed out that the composition emerges from the machine hind part
foremost and upside down as it were. This enables the justification
holes, which were originally punched at the _end_ and not at the
beginning of each line, to direct the proper casting of the spaces in
the lines to which they correspond.

It will be seen, therefore, that the casting portion of the monotype
machine is actually automatic. It performs all its operations without
human assistance or direction. Occasionally it will stop of its own
accord and refuse to work, but this merely means that it has found
something amiss with the perforated instructions, a mistake as to the
length of a line or so forth, and it refuses to continue until the
workman in charge of it puts the error right, then it starts on again
and continues on its even course, casting letters and spaces and
punctuation marks, and arranging them first in words, then in lines,
next in paragraphs, and finally in a column on the galley.

The casting-machine works at so high a rate of speed (casting from one
hundred and forty to one hundred and fifty characters per minute) that
it can in its output keep well ahead of the operator on the keyboard.
This, however, so far from being an inconvenience or leading to any
loss of time, is an advantage, for four casting-machines, which can
easily be looked after by one man and a boy, can cope with the work of
five keyboard operators, or if all are engaged on the same character
of composition two casters can attend to the output of three
keyboards. This suggests a reference to the facilities offered by the
machine for the production of matter composed in various faces of
type. The machine casts practically all sizes in gener