_How Type is Made_
[Ill.u.s.tration: Solid lines indicate one half of the mold. Dotted lines show the other half in position. Shaded portion represents type metal filling aperture in the mold. The molten type metal flows through the opening at A, down to the side B, where the matrix (not shown in this diagram) molds the face of the type. The tag of metal, called the jet, marked C, is cut off after casting. D is a narrow f.l.a.n.g.e on the mold which forms the nick on the under surface of the type body.]
The mold in which type is cast consists of two essential parts--the steel box in which the body is formed, and the matrix which contains a sunken image of the character. The matrix covers the opening at one end of the mold, and on the opposite end (which is the foot of the type) is an opening through which the melted metal is injected. A mold is made for a single body-size of type but it is adjustable sideways to correspond to the various widths of the letters in an alphabet. One mold may be used to cast, in succession, all the letters of a font of type, or it may be used to cast any number of fonts of different faces that may be made on the same body, by merely changing the matrices that form the face. The mold is made in two sections, which are fitted together so as to close up to the required width of the letter, and, after the cast is made, to open slightly in order to release the type.
[Ill.u.s.tration: Matrix]
_The Matrix._ There are three different methods of making type matrices. By the oldest method the first step is to cut the character on the end of a small bar of soft steel, called a punch; when this is done, the steel is hardened and it is used to stamp an impression in a bar of copper. This copper bar is a matrix in the rough, and its sides are next trimmed and squared so that it will fit the mold.
[Ill.u.s.tration: Type-mold complete, in two parts, but without the matrix (which is shown separately above). Position of the matrix when cast is made is indicated by the letter H on the end of the type within the mold.
The upper and lower halves of the mold slide horizontally, to make the interior casting-box wide or narrow to conform to the required widths of various letters.]
The second method of making a matrix is by electrotype process. The original pattern of the letter may be engraved by hand or by other operation, or it may be a perfect type-face of a previous casting.
This is fitted into a small frame of bra.s.s and then held in the vat of an electro-galvanic battery, which deposits a thick film of copper around the pattern and fills the opening in the bra.s.s frame. When this electro-plating process is completed, the pattern letter is extracted and the bra.s.s frame, with its copper impression of the letter, becomes the essential feature of the matrix. It is then reinforced by riveting another plate on the back, and is trimmed and fitted to place on the mold.
A third process of making matrices is with an automatic matrix-cutting machine, in which the shape of the desired letter is cut in the face of a plate of composition metal by a small rapidly-revolving cutting point. A large pattern of the letter is placed in one part of the machine, and while the operator traces the outline with the point of a lever all the motions are duplicated in miniature by the cutting tool on the bar of metal, which becomes, when completed, a matrix.
_Casting the Type._ The old-time method of casting type was with hand molds, the melted metal being poured in at the foot of the mold with a small ladle while the mold was held in the hand. In the modern casting machine, the mold with its matrix, is a.s.sembled by the side of the metal pot, in which the metal is kept at a uniform temperature by means of a gas furnace.
In the center of this metal pot is a rod with a spring attachment which, at each operation of the machine, acts as a plunger to force a small stream of hot metal through a side aperture into the jet-hole of the mold. After the casting, the two parts of the mold separate slightly, the matrix is drawn away from the face of the type, and the cast is moved out; then the mold and matrix close together again and the operation is repeated. Cold water or air is circulated near the mold to keep an even temperature. The matrix for one character only is placed in the machine and when enough types have been cast, it is taken out and replaced by another, the change usually requiring but a few moments.
There are several kinds of type-casting machines in use, such as hand casters, steam casters, and automatic casters. The older style is the hand caster, which is operated by a small wheel with a handle attached. Steam casters are operated by mechanical power (originally steam power).
When type is cast by a hand machine it is unfinished, as a piece of metal called the jet still adheres to the bottom of each type. This jet is broken off, and the types are set in long lines and fastened in a narrow channel, face down. A small plane smooths away the rough surface caused by breaking off the jet. This leaves a shallow groove on the bottom of each type and allows it to stand squarely on its feet. The types also have slight burs and sharp edges of metal which must be rubbed off before they are ready for inspection and for the font-room. Type cast on the older "steam" machines require the jet to be broken off after the casting, and the final finishing of the type is done afterward by other operations. These finishing touches are done mostly by hand, with the aid of a polishing stone or a small dressing wheel.
On the automatic machine, which is the modern method of casting type, breaking off the jet, rubbing, dressing, etc., are all accomplished automatically on the machine, the types coming out in a continuous line practically ready for the compositor"s case.
The foregoing describes in a general way the methods of making type by the regular founders. There is now a great deal of type made by automatic composing and casting machines installed directly in many composing rooms.
Two distinctive styles of these machines are now extensively used--the Linotype and the Monotype. Both of these have reached a high degree of efficiency because of their nice mechanisms, based on the principle of automatically operated molds, matrices, and delivery devices.
In the Linotype the matrices for a desired line of words are a.s.sembled side by side and the line is cast in one piece.
In the Monotype the mechanism automatically and rapidly adjusts the matrix of the desired letters one at a time over the mold, and each type is cast and moved along into lines and then into a column on a galley.
_The Linotype_
The Linotype (line-o"-type) consists of a mechanism for a.s.sembling bra.s.s dies or matrices in lines, presenting them in front of a mold in which a type-high metal bar, or slug, is cast, and returning the matrices to their respective channels for use again. The bra.s.s matrices have the characters of the alphabet, figures, points, etc., sunk into their edges; these are held in a magazine, which is an arrangement of channels in an inclined position above a keyboard. By the pressing of a key the required matrix is released, which drops and is carried into place by a small belt. Wedge-shaped s.p.a.ce-bands are also controlled by a key, and when sufficient matrices and s.p.a.ce-bands are a.s.sembled to make the line a bell rings. By operating a lever the line of matrices then moves in front of the mold inserted in the side of a wheel and behind which is a pot of melted metal.
[Ill.u.s.tration: Four-Magazine Linotype Machine]
By the next operation the s.p.a.ce-bands are pushed between the words, thus spreading them to the measure. The line justified, a plunger in the metal-pot forces a quant.i.ty of metal into the mold and against the line of matrices, forming a metal strip or slug with the letters in relief on one edge. After the cast is made, a turn of the mold-wheel and other mechanism shaves off the surplus metal on the foot of the slug and pushes it between knife-edges, where it is trimmed on the sides, and is then pushed on to a galley. The melting of the metal is done by a small gas furnace under the metal-pot.
After the matrices have been used for the line they are lifted by an arm to the top of the machine and distributed again, each character in its particular channel in the magazine. The matrices for each character have a set of notches or teeth different from every other character; and as they are moved along the distributing apparatus by horizontal screws each matrix reaches a point where its notches are matched and it drops into the top of its channel. There are a number of matrices of each character, and the arrangement of the machine is such that three lines of matrices may be kept in operation at once--one being a.s.sembled, one at the casting mold, and the third being distributed.
The work of the operator is to manipulate the keyboard and, at the end of each line, move a lever which engages the mechanism that carries the a.s.sembled line to the mold. All other operations are performed by mechanical power.
_The Monotype_
[Ill.u.s.tration: Monotype Keyboard]
The Lanston Monotype is a type-casting machine which produces separate types set in lines of any length, up to sixty ems pica, s.p.a.ced and justified. It is in two parts--a keyboard and a casting machine. The function of the keyboard section is to punch a series of holes in a moving strip of paper, which unwinds from one spool to another, pa.s.sing under a series of punches in its journey. The punches are operated by pressing the keys on the keyboard, the result of this operation being a roll of perforated paper ribbon. This ribbon is then taken to the casting machine, which contains a pot for melted metal, a stationary mold for the size of type to be cast, and a matrix-plate.
The matrix-plate is about five inches square, and has on its face depressed images or matrices of each letter and character of the font.
The perforated strip of paper, when fed to its place, controls the movement of the matrix-plate, so that the required letter is adjusted exactly in place over the mold, while the melted metal is squirted in to form the type. The type then moves away and takes its proper place in the line, until the line is completed, when it is automatically moved out on to a galley.
The Monotype keyboard, being an entirely separate machine, may be and usually is operated in any place away from the casting apparatus and work may be executed on it anytime before casting. The perforated roll may be fed through any number of times to produce duplicate castings of the matter, and a matrix-plate for a different face may be used if desired. In the casting of the line the proper s.p.a.ces are cast with it, the s.p.a.cing needed to justify each line being indicated on the perforated record during composition on the keyboard.
[Ill.u.s.tration: Monotype Casting Machine]
A peculiarity of Monotype composition is that, while the keyboard produces the perforated roll in the usual sequence from beginning to end of the story, the casting machine reverses the process by starting at the end of the composition and finishing up with the beginning.
_Ingredients of Type Metal_
The metal used for casting type is a mixture of lead (five parts), antimony (two parts), tin (one part), and sometimes a small addition of copper. Lead forms the chief part of all type metal, as it melts easily and fuses readily with other metals; but lead alone is too soft for the service required of type. Antimony is brittle and gives hardness, and tin is added to impart toughness. Lead and antimony in approximately these proportions make an alloy which has the unusual quality of expanding slightly, instead of shrinking, when cooling, thus permitting a full, sharp cast in all parts of the mold. Tin flows readily when melted and increases the smoothness of the cast on the surface of the mold. A small quant.i.ty of copper may sometimes be added to give still greater toughness.
The metal used for small sizes of type is commonly harder than that used for the large sizes, the softness of the metal gradually increasing with the size of type made. Script types and faces with delicate lines are usually cast with metal a little harder than that used for the normal and bolder faces.
The foregoing refers more particularly to type cast by the regular foundries. The metal used in automatic casting machines, like the Monotype, contains a larger proportion of lead and less antimony; while the metal used for casting line-slugs in the Linotype machine is composed of still larger proportion of lead and very little of the other two metals. Stereotype metal and metals used for leads, slugs, furniture, etc., are largely lead.
_Wood Type_
Large types, such as are used for posters and large bills, are made of wood. The smallest size for practical use is 48-point, or 4-line pica.
Sizes of wood type are multiples of the pica, and are so named, as 8-line, 10-line, etc. They are much cheaper than metal types, though not as durable or satisfactory for printing. The wood commonly used is maple, and the letter is made on the end of the grain. It must be well seasoned and polished. Pine and other soft woods are used for very large sizes of wood type and poster engravings.
The manner of cutting the letter is by routing away the blank parts with a small rapidly-revolving cutter. The strip of wood, large enough to make several letters, and planed type-high, is placed in a machine equipped with a pantagraph apparatus. A pattern letter is put in place, and over this a guide-point is moved. On another part of the machine is the revolving cutting tool. As the guide-point is moved over the pattern its motions are duplicated on the block under the cutting tool, which cuts away the wood. When the letters on a block are thus routed out, they are sawed apart, the finishing touches given, and the letters oiled.
SUPPLEMENTARY READING
The Invention of Printing. By Theodore L. De Vinne. Oswald Publishing Co., New York. Cloth, 557 pp. $6.
Plain Printing Types. By Theodore L. De Vinne. Oswald Publishing Co., New York. Cloth, 476 pp. $2.
The Monotype System. Published by the Lanston Monotype Machine Co., Philadelphia. 294 pp. and diagrams.
The Mechanism of the Linotype. By John S. Thompson. The Inland Printer Co., Chicago. 216 pp. $2.
History of Composing Machines. By John S. Thompson. The Inland Printer Co., Chicago. Cloth, 557 pp. $2.
Specimen Books of American Type Founders Co.; H. C. Hansen, Boston; Barnhart Brothers & Spindler, Chicago; Keystone Type Foundry, Philadelphia.