If the reader will notice the type in which this volume is composed, he will observe that the bottoms of the tail letters are very close down upon the tops of the tall letters, and all but touch: this is termed solid. When a page or book is required to look light and less wearisome to the vision, the lines of type are removed from each other, and a space-line inserted between them—the page is now termed leaded. These space-lines used to be cut, by the compositor, from milled lead, first in strips of the necessary width, then of the required length; hence the term leads, by which name they are commonly known. However, they were but poor appliances at the best. Moulds are now used for casting the metal to the specified thickness in strips of about 9 inches long, then cut by a machine to a set gauge; by these means the thickness of the space-lines, or leads is not only more uniformly secured, but far greater regularity obtained in the lengths cut. Here, as in the large type, as above mentioned, Pica is the standard which regulates the lead; in other words, leads are cast as 3 to a pica, that is, 3 leads form the solid measurement of the Pica body; 4-to-pica requires 4 leads, and the body of the lead continues to decrease according to the prefixed figure, which simply denotes into how many parts the pica is to be divided. Leads are
cast so delicately fine that 16 form the pica, but they are seldom used. In many of the News offices brass space-lines have superseded those cast from type-metal.
The method of manufacturing type is—
The face having been determined upon—light or heavy, round or narrow, as well as the thickness of the downstroke—a piece of prepared soft iron is taken, and upon the tip-end thereof the proposed letter is cut in relief; when this cutting is finished it is case-hardened, and afterwards styled the punch. The strike is the next operation. The punch (the letter cut upon which, by-the-bye, is backward) is now punched, or struck, into an oblong piece of copper, about 3 inches long and 1⁄3rd of an inch thick, the breadth such as the size of the letter may require: this is the matrix. A most particular part has now to be performed, called justifying; which means that the matrices shall, when placed in the mould, deliver the letters perfectly upright, and all to be true on a line as fine as a razor’s edge. When the process of justifying is accomplished, the matrix is fixed at the bottom of a mould, of the shape of a parallelogram, of the size of the body one way, of the width of the letter the other, and the depth the standard height of the type; the molten metal is forced down this tube, either by hand or by a pump worked by hand or steam, the metal filling the matrix (the sunk letter upon which is now forward) receives the shape of the letter, which is once more reversed, or in a backward position, like as the original punch was cut. The castings are released from the mould by a very ingenious method of opening from the two diagonal corners. The types as cast are forwarded on to the dressers to remove burrs and other superfluities; then are placed in long lines in a frame for finishing; next turned face downwards, and a grooving plane driven across the feet to insure correctness in height; finally looked over for blemishes, when all faulty letters are thrown out; the process is completed by ranging into lines of handy length, and tied up—ready for delivery to the typographer.
PRINT′ING INK. Prep.—a. The VARNISH. Linseed or nut oil, 10 or 20 galls., is set over the fire in an iron pot capable of containing fully as much more; when it boils, it is kept stirred with an iron ladle, and, if it does not take fire of itself soon after the smoke begins to rise, it is kindled by means of a piece of burning paper, stuck in the cleft end of a long stick; the pot is shortly afterwards removed from the fire, and the oil is suffered to burn for about half an hour, or until a sample of the varnish cooled upon a palette knife may be drawn into strings of about 1⁄2 inch long, between the fingers; the flame is now extinguished by the application of a closely fitting tin cover, and, as soon as the froth of the ebullition has subsided, black resin is added, in the proportion of 3⁄4 lb. to 1 lb. for every quart of
oil thus treated; the mixture is next stirred until the resin is dissolved, when dry brown soap, cut into slices, 13⁄4 lbs., is further added (cautiously), and the ingredients are again stirred with the spatula until the whole is united, the pot being once more placed over the fire to promote the combination; when this is effected, the varnish is removed from the heat, and, after a good stirring, is covered over and set aside.
b. The INK. Indigo and Prussian blue, of each, in fine powder, 21⁄2 oz.; mineral lampblack (finest), 4 lbs.; vegetable lampblack, 31⁄2 lbs.; stir them gradually into the warm varnish (a), and submit the mixture to careful grinding, either in a mill or by means of a slab and muller. On the large scale, steam power is now generally employed for this purpose.
An extemporaneous superfine black ink may be made by the following formula:—Take of balsam of copaiba (pure), 9 oz.; lampblack, 3 oz.; indigo and Prussian blue, of each 1⁄2 oz.; Indian red, 3⁄4 oz.; yellow soap (dry), 3 oz.; grind the mixture to an impalpable smoothness by means of a stone and muller. Canada balsam may be substituted for balsam of copaiba where the smell of the latter is objectionable, but the ink then dries very quickly.
Coloured printing inks are made in a similar way from the following pigments:—Carmine, lakes, vermilion, chrome yellow, red lead, orange red, Indian red, Venetian red, for red; orange chrome, chrome yellow, burnt terra di sienna, gall-stone, Roman ochre, yellow ochre, for orange and yellow; verdigris, Scheele’s green, Schweinfurt green, blues, and yellows mixed, for greens; indigo, Prussian blue, Antwerp b., cobalt b., charcoal b., for blue; lustre, bronze powders, &c., for metallic colours; and umbia, sepia, &c., for brown.
Obs. It is necessary to prepare two kinds of varnish, varying in consistence, from more or less boiling, to be occasionally mixed together as circumstances may require; that which answers well in hot weather being too thick in cold, and vice versâ. Large characters also require a thinner ink than small ones. Old linseed oil is preferable to new. Yellow resin soap is preferred for black and dark-coloured inks, and white curd soap for light ones.