An illustration shows the two-letter matrices of a special Mergenthaler machine. The upper is usually a body character and the lower an italic, a small capital or a black face. These lower matrices are lifted a little by a key so as to come in line with upper matrices. In this way the compositor has at command two distinct fonts. Groove E receives the ears of the matrices. In a normal position D receives the ears of the matrices elevated to produce the secondary characters. In this way the matrices are held in position as casting proceeds. Five double-wedge justifiers will be observed between the matrices. These devices, invented by J. W. Schuckers, form an essential part of the machine. Justification, let the reader be reminded, is so spacing the contents of a line that it shall neatly end with a word or syllable. In typewritten manuscript the lack of justification leaves the ends of lines jagged and unsightly. Mr. Schuckers at the end of every word places a pair of wedges. When the operator is close to the end of a line he pushes in the whole row of wedges in that line; the outer sides of each pair remain always parallel, and as pushed in these outer sides are just sufficiently forced apart to space out the line with exactitude. To lift a table or a desk, and at the same time keep it always level, we may use pairs of wedges in the same manner; they must, of course, be much larger and thicker than those used in linotypy. See next page for an illustration. [Illustration: A, two wedges partly in contact. B, two wedges fully in contact, outer sides parallel.] To-day a book may be reproduced without any recourse whatever to the type long indispensable. A photographer takes the volume, and repeats it in pages of any size we wish, dispensing not only with the type-setter or the type-caster, but even with the proofreader, since a camera furnishes an exact _fac-simile_ of the original work. If the book is illustrated, a further economy is enjoyed; its pictures are copied as faithfully and cheaply as the letterpress. Ingenuity in Copying and Decorating.