when the "copy" to be set consists of what is technically
termed "tabular" matter, the various columns of figures or so forth
composing it are not composed vertically but horizontally and so each
section must of necessity be justified separately.

Should the compositor be required to "over-run illustrations," as the
term goes, in other words to leave a space in which the "block" for a
cut may be inserted, so that it may have type all around it or on one
side of it only, the machine offers no difficulty at all. All that the
operator has to do in this case is to carry the composition of each
line as far as necessary and then complete it with a row of "quads,"
or spaces. Thus, when the composition is cast by the casting-machine
the space into which the block is to fit is occupied by a square of
"quads." These have only to be lifted out, the block inserted, and the
trick is done.

We will then imagine that the operator has finished his task. Of the
bank of two hundred and twenty-five keys in front of him (the
equivalent of a full "font" of type, with figures, italics, and
symbols complete), he has depressed in turn those necessary to spell
out the words of his copy, he has put a space between the words he has
justified in accordance with the dictates of the justifying dial, has
arranged the spaces for the insertion of blocks or illustrations, and
as the result of his labors he has merely a roll of perforated paper
not unlike that which operates the now familiar pianola or
piano-player. Yet this roll of paper is the informing spirit, as it
were, of the machine. Its production is the only portion of the work
of the monotype for which a human directing agency is necessary, every
other function being purely automatic.

The roll of perforated ribbon is lifted off the keyboard and put in
place on the casting-and setting-machine. As it is swiftly unwound it
delivers to the casting-machine the message with which the operator
has charged it. Through the perforations he has made compressed air is
forced. Now, as has been explained, the holes correspond to the
characters or typographic symbols of the "copy," and the jet of air
forced through them sets in motion the machinery, which controls what
is known as the "matrix-case," a rectangular metal frame about five
inches square, which contains two hundred and twenty-five matrices, or
little blocks of hardened copper, each one of which is a mould
corresponding to a character on the k