While wood has thus found a rival in pulp, stone has a new competitor much more formidable. Pavements and piers are often needed in long stretches, without joints for the admission of rain or frost. The demand is met by cements and concretes easily laid in unjointed miles. These materials when strengthened with skeletons of steel find many uses; a brief survey of them is given in this book. A sister product, terra cotta, baked at high temperatures, is now molded in beautiful designs not only for tiles, but as walls, cornices, finials, vases, hearths, and statuary.
[Illustration: Mergenthaler linotype, showing five double wedges for justification.]
Clay as tablets was one of the first mediums of the printer’s art, an art of late years exposed to many a surprise from unexpected invaders. Composition is now performed by machines of various models, one of them being Mergenthaler’s linotype, as employed for this book. In effect this machine is a caster rather than a compositor, and recalls the chief tasks of the type-foundry. As an operator touches its keys he releases a succession of matrices, from which is cast a line as a unit. In its latest form this machine enables the operator to change instantly from one font to another, introducing roman, italic, and black face type in the same line at will. Intricate book, tabular and pamphlet matter, with chapter headings, titles, or marginal notes may in this new model be set up at a speed four to six times quicker than hand composition.
[Illustration: J. W. Schuckers’ double-wedge justifier.]
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.