Stereotyping.—Plaster Moulds.—Planing and Beveling.—Correcting Stereotype Plates.—Process of Electrotyping.—The “Guillotine.”—Ornamenting.
The invention of stereotyping is also a great improvement in printing. Almost all works, after being put in type, are stereotyped; the advantage is that a new edition can be struck off as often as called for, without the labor of resetting the type.
The process of stereotyping differs from common printing, in that the letters, after being set up, are cast in plates of entire pages, from plaster of Paris moulds.
The workman in the picture is about removing the moulds from the type beneath. The mould, forming a perfect fac simile of the page intended to be printed, is placed with others in a great oven, where it is dried and baked hard. The edge of the oven can be seen at the right of the picture on the following page, which represents the interior of the Stereotype Foundery.
While the plaster mould is baking in the oven, the foundery man is getting things in readiness for converting it into lead. Upon the left, in the picture, is a high pile of bars of lead, looking like an irregular chimney. When the bars of lead are put into the cauldron to melt, a certain amount of antimony is put in also, to render it brittle, and tin is added to give a brightness of surface. When the lead, antimony, and tin are well melted, and the scum has been removed, the composition is poured into iron moulds, where it hardens, and comes out in the shape of the lead that was put into the kettle in the first place. These bars of composition, lead being by far the largest material, are put into the boiler over which you see the man working, and melted again, making a molten mass, which is kept liquid by the hot fire beneath and the frequent stirring. When the plaster pages, or moulds, are well baked in the oven, they are ready to be plunged in their lead bath. An iron pan about two feet long, a foot broad, and two or three inches deep, is the vessel, in which is laid a false bottom of iron, called a floater; on this are laid the plaster moulds, face down, and the whole is covered with an iron slab, which does not, however, rest on the plaster moulds, but upon the edge of the iron pan. An iron handle, like that of a basket, is secured to the middle of the pan upon the wooden stand in front of the picture. A crane overhangs the boiler, and from it drops a hook surrounded by four legs; the hook takes hold of the hole in the handle, and the four legs press upon the iron cover of the pan; the crane swings round, holds the iron pan with its plaster moulds snugly shut up in it, and suspends the body over molten lead, lowering it until it is partly sunken in the lead but not wholly plunged in it.
The four corners of the pan are not square; and as the iron cover does not fit into the grooves, there is access to the interior of the pan by this means. Down them, then, the founder pours the lead, dipping it from the boiler, until it fills up completely all the little type openings in the plaster moulds. Then the crane lifts it and swings it over to the trough by which the boy is standing. It is lowered into the water to cool, after which a crane swings it over to the wooden standard, where one is waiting to be opened. The handle is removed, and then the founder, taking a heavy hammer, knocks off the lead at the corners and edges, where it has sealed up the iron lid on the pan. The cover is removed, and the contents of the pan taken out. The plaster is chipped off and thrown away; but now are seen lead plates of the size of the plaster moulds, having their surface raised in letters, just as that of the moulds was sunken in letters. The plates are about double the thickness of the slates used in schools.
These plates are cooled, and washed free of plaster in the trough,—the boy in the picture is now doing this,—when they are ready to go into the finishing room, to be trimmed, planed, picked out, corrected, and generally made ready for use in the printing-office.
In the first place, the plate is trimmed at the edges, and planed in a planing-machine, which shaves off, from the back, strips of the rough lead. It is beveled also; that is, the edges are shaved down in the left hand of the three smaller machines shown in this picture: the object of the beveling is to secure the plate afterward, when it comes to be put on the press. It is also picked out: a workman goes over the lettered surface with a sharp tool, clearing out letters which have accidentally become filled up with lead, and correcting all inaccuracies of form which he discovers.
The man at work in this picture is planing the back of the plate again, for the purpose of getting the requisite thickness. The knife in this plane makes one shaving of lead, which rolls up as it leaves the plate, like any fine shaving. To take off another shaving, a piece of pasteboard is placed under the plate, by which it is raised a trifle higher, and so again brought under the knife.
Correcting Stereotype Plates.
A proof is taken on a common hand-press, and with this proof before him the corrector marks such letters as were overlooked when the plate was picked out. This proof goes into the proof-reader’s room again, who now goes once more over the page, to see if everything is right; and after he has marked it, back it goes to the corrector, who now, with the printed proof-sheet before him, makes the corrections that are required. If, for instance, a letter is set up wrong, as pan for pen, and has been overlooked by the proof-reader, and the plate is cast, what is to be done?
The corrector takes a sharp tool, and punches a hole through the plate where the interloper is, just the size of the type, and then restoring a common type e, through the opening, cuts it off even at the back of the plate, and solders it in its place with lead. In this way a whole line of type is sometimes introduced for an incorrect line in the plate. The corrections being made, the plate is ready for the press. When not in use, the plates, being very valuable, are carefully put in a box,—a large book requiring several boxes. They are stored in fire-proof safes, made for this purpose.
While books are generally stereotyped, woodcuts are always electrotyped. Instead of being moulded in plaster, the cut or illustrated page goes into the electrotype room, to be moulded in wax.
Let us look at the process.
A brass case, or very shallow, oblong pan is filled with liquid beeswax, which stands until it has hardened. The form containing the pages of type, well covered with fine black lead, is placed upon the bed of the press, shown in the picture; the face of the type is uppermost. There is an upper bed, which in the picture is swung half-way back. This is swung all the way back, and upon it is secured the brass case of wax. When the upper bed is brought back again, the wax face will of course be downward, and thus will be ready to receive an impression from the form of type resting on the lower bed; this lower bed is movable, and is gently raised by a screw until it presses into the wax, after the press is tightened, and now the soft wax receives the exact impression of the type; and the upper bed being swung back, the brass case, with its wax mould, is removed. We have got just as far, in fact, as when the plaster in stereotyping was ready to receive the casting. In the battery, a corner of which is seen in the picture, are hung one, two, three, or more copper plates; and from rods running parallel are hung the cases containing the wax moulds, one being hung on either side of the brass plate facing it. The positive pole is attached to the case, the negative to the copper plate; and the connection being made, a thin film of copper appears on the surface of the mould. This coating increases the longer the mould remains in the battery. After ten or twelve hours it is removed, and the result is a shell, as it is called, of the thickness of thin pasteboard, the upper surface a perfect fac simile of the original page of type or wood-cut, every line, and every imperfection too, being reproduced. The under surface is exactly parallel; for each projection on the upper surface there is an indentation in the lower.
This thin shell of copper can be bent and crumpled up; it could not be used for printing in its present state, and it passes through a process called “backing up.” A thin coating of tin is applied to the back, when it is put face downward in a shallow dish, and kept in place by a number of small elastic rods. Then it is hung over a flat cauldron filled with melted type-metal, and lowered to rest in it. When the plate has acquired the same degree of temperature as the metal, the latter is ladled and poured over the plate, filling up all the hollows and indentations, and forming a solid back of lead. The coating of tin is first applied, as lead will not adhere to copper.
The plate, being now ready for the planing, beveling, picking, and correcting of stereotype plates, goes through the same process that we have before described.
When a book is to be bound, the pile of sheets which form it is made even at the back, and a saw, working by steam, cuts shallow grooves across the back, for the twine over which the sewing is done. Two girls are pictured sewing at their frames,—passing the needle through the fold of the sheet and round the upright twine, adding one sheet at a time to the pile, until the entire book is sewed. In the large apartment called the forwarding-room, the remaining processes of finishing are done. The rough and uncut edges of the book are made smooth by means of a cutting machine called the “guillotine.”
The edges of a number of books can be cut at a time, by being secured on a movable bed, which rises so as to bring them under a stationary knife, which cuts them smoothly as they are pressed against it.
There is also a backing-machine, for rounding the backs of books. The book is placed in a vise, and held near the edge of the back; and the man, working a treadle, moves a heavy roller over the back, thus drawing up the sheets in the centre; this is that the cover may be made fast to the book, the sides of the cover fitting tightly; the limp back is like a hinge. The stiff pasteboard covers are made by themselves; for instance, if a thousand copies of a book are to be made, while the folding and sewing of the thousand books is going on in one part of the building, in another two or three men are at work making cases; and when each is finished, they are put together.
But the stamped name on the back or ornamental work is done on the cases, after they are covered with cloth, and before the books are fastened into them. A brass die, or brand, is made of the title of the book; then the covers which are to be stamped are taken by the gilders, who first rub the white of an egg over the surface to be stamped, and upon that lay thin gold leaf, of gossamer lightness.
In the picture three girls are laying on the gold leaf with their pallet knives.
The covers are now ready to be stamped by the brass die, and that is put in place in the embossing press, seen behind the gilders. It is kept constantly heated, and is attached to the upper part of the press with its face down; the cases are slipped singly into the press, and pressed up against the die, the letters of which stamp the gold into the cloth; the rest of the gold is carefully rubbed off, and collected and preserved.
When the edges of the leaves are to be gilded, it is done by holding the books firmly in a vise, as seen in the cut, the gold leaf being laid on with a pallet knife; after which the surface is polished.
The workman is seen polishing the edges with an agate burnisher. The sheets having been pasted in their cases, and thoroughly subjected to a powerful press, are packed and put into the trade.
Another very curious process is marbling the edges of leaves.
In the engraving is a long trough, in which is a thin mixture of water and gum tragacanth, over which the workman holds two dictionaries in his hands. The colors which combine in the marbling are water-colors, and are distributed in the seven jars with brushes. The marbler shakes one of these brushes over the vat, the color falling is held on the surface by the glue, and little circles of blue, or whatever was dropped, are scattered over the water; with another brush he sprinkles in the same way, and so on for any number of colors, producing effects as gorgeous as the mingling colors of autumn leaves or of sunset clouds. If a piece of paper now were dipped into the trough, it would, when removed, be mottled or marbled. The marbling is elongated or streaked by slowly passing a coarse rake through the water. The marbler, taking two books, dips the edges into the trough; the gum causes the colors to adhere to the paper, and the precise pattern in the vat is elegantly painted on the book; the next is dipped in a different place, and when the surface has been taken up, the scum is skimmed off, and the colors again sprinkled on the water, and the process repeated as long as required.
