Fig. 584 shows the general principle of the printing-machine: a is the roller, on which the pattern is engraved ; it is mounted so as to revolve against two other cylin ders b c. The latter is covered with woollen cloth, and, as it revolves, it dips into the trough d, containing the colour properly mixed. Some of the colour thus taken up is transferred to the pattern-roller a. The other cylinder or drum I is of iron, covered with several folds of woollen cloth or felt, to give an elastic surface. Round the drum, travels an endless web of blanketing e, iu the direction of the arrows, and over this, so as to come into direct con tact with the roller a, passes the piece to be printed f.
To prevent a taking up superfluous colour, it is scraped as it revolves by a sharp plate of steel, or alloy of nickel, called the "colour-doctor," g; on the opposite side, is a similar plate, the "lint-doctor," to remove any loose fibres from the roller. The rollers h and troughs i, shown in dotted lines, represent the arrangements required if more than one colour has to be printed upon the cloth.
A four-colour machine is seen in end elevation in Fig. 585, and in section in Fig. 586. A is the cast-metal frame-work, bolted down by the bolts B ; C is the drum, about 2 ft. in diameter, and 3-4 ft. in length, according to the kind of cloth to be printed ; D are the copper pattern-rollers, of the width of the piece; E are mandrels, on which the roller is forced by a screw-press, about 4 in. ju diameter where the roller is fixed, but the journals are narrower. Within the roller, is a pro jecting piece or " tab," extending all the width, and fitting into a slot cut in the mandrel, to prevent slipping. The bowl or pressure-cylinder C rests with its gudgeons in bearings or bushes, which can be moved up or down in slots in the side-cheeks A ; these bushes are fixed by strong screws F, turning in nuts screwed to A, to counteract the pressure of the two lowest rollers. The sliding pieces G support the bearings of the mandrels, colour-boxes, and doctors, and move in arms of the frame-work, by means of screws H, working in female screws I, and forming a portion of the set of jointed levers K. They give further pressure to the rollers D. The two uppermost rollers press against the cylinder by the levers IC, which are joined to the ftame-work at f, and to the inside of the main frame g and M, as fulcrums, and are jointed together at h. The bent levers h g i fit into the sockets i of the horizontal levers M K, loaded with movable weights at K. The two lower rollers are pressed against the cylinder in an analogous manner.
The perrotine may be described as a machine for doing a style of work almost the same as block printing. It works three wooden blocks, each 2-5 in. in width, and varying in length according to the width of tbe piece. Upon these blocks, the pattern is engraved. They can be mechanically brought down upon the front, top, and hack of a four-sided iron beam, faced with cloth, over which the pieces travel. The perr6tine produces effects in three colours, which could not be obtained in hand-printing, without blocking the pieces three Limes over. It even executes some styles of work which the cylinder-machine cannot perform without the aid of the "surface-roller." This latter machine, which has been developed in Scotland and England to work with only a man.and two boys in attendance, does as much work as 200 men and boys could complete by hand
printing, and has been constructed to perfect at once patterns of 12, and even 20, colours.
The perrotiue is shown in a vertical section in Fig. 587, and in elevation in Fig. 588: A represents the cast-iron framework; B, cast-iron tables, planed smooth, over which revolve the blanket, the back-cloth, and the piece to be printed ; C, sliding pieces, to which are screwed the block-holders 3, and causing the engraved blocks 2, to move alternately against the woollen surface where they receive the colours and the goods to be printed, by the action of the arms 4, 5, whose supports 6, rest on the frame A, and act on the beams 7, keyed to the slides c. The lower of these slides, being in a vertical position, takes by its own weight a retrograde movement, regulated by R. counter-weight. E are movable colour-sieves, keyed to connecting-rods, and receiving from the power applied to the machine the kind of movement which they require. These sieves, which are flat, and covered with cloth on the surface opposite to the blocks, slide in grooves on the sides of the tables, and receive from the furnished rollers the colours which they afterwards transmit to the blocks. F are troughs, filled with colour, and each furnished with rollers 8 10, the last of whioh, dipping into the troughs, arc charged with colonr, which they communicate to the rollers 8, covered with woollen tissue, and these again transfer the colour to the sieves E, where it is spread by the fixed brushes 9. To vary at will the quantity of colour enpplied, the rollers 10 are connected with levers 11, which, by means of adjusting screws, bring them into contact more or less close with the rollers 8, and thus regulate the charge of colour. The blanket, back-cloth, and pieces are made to travel thus : at the four angles formed by the three tables B, are rollers 1, fitted on their surfaces with needle-points, to prevent tho pieces from slipping as they pass on, and thus to secure tho regular progress of the goods, which is determined by the toothed wheels 21, fixed at the extremities of the axles of the rollers. G is a roller for stretch ing the endless web, resting with the ends of its axle on two cushions, forming the extremities of the screws 12, by which the roller can be pushed further out if needed, to give the required tension ; H is another tension roller, supporting the blanket and back-cloth. K is a roller which serves similar purposes for the blanket, the back-eloth, and the tissue being printed ; T, the blanket, which passes over the semi-circumference of the roller G, passes over H, and behind K, to circulate around the cylinder I, and the surface of the table B ; L is a cylinder, from which the backcloth is unwound, after being stretched by H, and smoothed by bars 13, whence it joins the blanket at K ; M is a roller, from which the pieces are unwound by the move ment of the machine, passing over the scrimping-bare 14, and joining the blanket and back-cloth at K, which it accompanies as far as the roller G, when it passes off, in the direction of N, to the hanging-rollers, where it ie dried.