Page:EB1911 - Volume 27.djvu/563

Rh continuous rate of 60,000 an hour. It consists of a horizontal mould wheel, 20 in. in diameter, contained in the casing D (fig. 6), in which are cut 100 radial slots, each having a matrix at its inner end. These slots thus form moulds, and are of varying width according to the letter each has to cast. Each wheel can only produce type of the particular body for which it has been cut, but by changing the matrices the moulds can be made to cast any description of face capable of being received upon the body. The wheel is rotated once in every six seconds, so that the slots are successively presented to a jet of molten type-metal, which is pumped from the metal reservoir A by a pump B of special construction and forced out at high pressure through a nozzle under the shield C. As soon as any particular slot has passed the jet and been filled with metal, a cam-action comes into play and gradually pushes out the formed type. This operation is completed in half a revolution, the ejected type being taken up by carriers mounted on a continuous chain E, which is moved along exactly in step with the wheel. The carriers, which are of different sizes according to the particular letters they have to hold, are raised by a cam-action as they come opposite the slots to receive the types, but fall again at the point F, depositing the letters at the end of the race G. Each successive type thus dropped pushes its predecessors farther along the race until when the row contains 200 types—the product of two revolutions of the wheel—an attendant lifts the whole series off and places them on the plate H, one row below the other. Since the sequence of the letters is of course the same in each revolution, the result is that each vertical line on the plate consists of the same character, and each sort can be easily removed and packed in any required form for despatch to the printer. As soon as each slot has been emptied of its type, another cam begins to draw in the matrix towards the centre of the wheel, so that it is in as far as it can go by the time the slot is again opposite the jet. To prevent a type from being drawn back with the matrix, the bead-cam K engages with the nicks which have already been formed on the front of the type-bodies by the operation of the machine. To ensure trueness and accuracy in the product, the conditions under which casting is conducted are maintained as uniform as possible. The composition of the type-metal alloy is kept constant; the temperature of the molten metal is carefully regulated by the aid of a pyrometer to about 800° F., so as not to volatilize the antimony it contains; the pumps work up to a pressure of 900 ℔ to the square inch, and by the interposition of a reducing valve deliver the metal at the nozzle at a constant pressure of 200 ℔; and the moulding slots are maintained at an equably cool temperature by an elaborate system of water circulation.



6.—Wicks Rotary Type-casting Machine.

Type-setting by Hand.—The types, received from the foundry in the packages called pages, containing about 8 ℔, are placed in shallow trays called cases. These contain compartments or boxes, each of which is appropriated to some particular sort or character. The cases when in use stand on frames or sloping desks. The case at the top is the upper case, and

that below the lower case. The former contains 98 equal-sized boxes, appropriated principally to the capital and small capital letters; the latter has 53 boxes of various sizes, appropriated to the lower case sorts. The difference in the size of the boxes corresponds to the difference of quantity of letters in a fount, the lower-case e, for instance, having the largest box. As a man picks out from the boxes seldom less than 1500 letters an hour and distributes or replaces on the average about 5000 an hour, it is necessary that the most economical allocation of the boxes should be adopted. The system of allocating the various types is called the lay of the case; one plan is illustrated in fig. 7.



7.—Type-case.

The types when taken from the cases are arranged in lines (composed or set up) in an instrument called a composing stick, made of iron, brass or gun metal. The slide in the middle is movable so as to accommodate varying lengths of lines. The compositor fixes the

“copy” or document which he has to repeat in type, in a convenient place before his eye. In his left hand he holds the composing stick, and with the thumb and first finger of the right hand lifts the letters from the boxes, and arranges them in the composing stick, every letter, point or sign being picked out separately. In this operation he is much assisted by the use of a setting-rule, a thin brass or steel plate which, being removed as successive lines are completed, keeps the type in place. When so many words and parts of words as will nearly fill the line have been composed, it is made the exact length required by increasing or diminishing the space between the several words. This is called justifying the line and is effected by means of the spaces already mentioned. If the work is not “solid”—that is, if the lines are not close together—the strips of metal called leads or brasses are inserted between each. When the composing stick is filled, the type is lifted upon a galley, a shallow tray of wood or metal, two or three sides of which are flanged, for the purpose of supporting the type when the galley is slightly inclined. Stickful after stickful of type is placed on the galley until it is full. The matter is then fastened up, a proof taken at the proof press, and the work of the reader or corrector of the press begins (see ). The proof, marked with the necessary corrections, is given back to the compositor, in order that he may make the required alterations in the type.

The type, being duly corrected, is made up into pages of the required length (unless the author has desired to see proof in slip). It is then imposed, that is, the pages are arranged in such a manner that, when printed and the sheet folded, they will fall in due numerical sequence. The impression from any arrangement of pages will be the reverse of that in which they are

laid down. If a four-page newspaper be opened and spread out with the first page uppermost, it will be found that on this side the order of pages is 4, 1; when turned the pages are 2, 3. The type pages must be ranged in the reverse way, as 1, 4; 3, 2. Thus the fourth page is placed alongside the first, because both must be printed together on the outside; the third page is to the left, and the second to the right, because in books the odd page—the verso—is always to the right. For a quarto a sheet of paper is folded twice, that is once across its breadth and then once in a perpendicular direction down the middle. It contains four leaves, and if these are printed on both sides eight pages. The two sides of a sheet are called the outer and inner formes respectively. A sheet of octavo is folded three times, making 8 leaves or 16 pages. The size of a book depends not only upon the number of times the sheet has been folded, and described accordingly as 4to, 8vo, 12mo, &c., but upon the size of the sheets. The dimensions of the papers commonly used in book-printing are: imperial, 22 × 30 in.; super royal, 20 × 27; royal,