The " breaker-card " is a powerful engine with a large cast-iron cylinder, 3-5 ft. diam., and 4-8 ft. across the face. This is mounted upon a strong frame, and is almost surrounded by a series of smaller rollers of the same breadth, called "workers " and " strippers," all of which are covered or clothed with steel pins, of a size suited for the special character of the work they have to perform. A " feeding-sheet " or revolving apron is attached to the back, upon which the tow is evenly spread and slowly carried to the feed-rollers, by which it is delivered to the revolving cylinder. These rollers are about 3 in. diam., and have a surface movement of about 18-24 in. a minute. The direction of the revolution of the cylinder, at the point where it receives the tow, is downwards ; and it consequently strikes the tow with great force in that direction. The pins with which it is clothed are generally about s in. long, and are iocliued in the direction of its revolution. These pins are set iu "lags" or staves of wood, secured to the cylinder by screws. They are IA- in. thick, 1 in. broad, and 24 in. long. The pins therefore protrude through them about in. The feed-rollers are also clothed with pins, those of the bottom one being slightly curved upward, as they present the tow to the pins of the cylinder, and therefore prevent the latter dragging in the material at too quick a rate. This resistance of the feed-roller secures a maximum of effective action, splitting and combing, on the part of the cylinder. It tends, however, to embed the fibre in its pins, and would, from this cause, soon destroy its efficiency, were provision not made to keep it clear. This is accomplished by the introduction of a third or " feed-stripper " roller, placed beneath, but sufficiently near for its pins, which are inclined towards the large cylinder, to strip the feed-roller by its greater speed. Iu its turn, it is stripped by the cylinder, whose surface• velocity is again much greater. The cylinder, baying received its full complement of tow, carries it forward to the "first worker," the second roller in the course of its revolution, which has about the same dimensions as the feed-stripper. This roller revolves at a slow rate, in a direction oppo site to that of the cylinder, and as its pins are inclined so as to receive and retain the fibre from the cylinder, the latter is cleared, the material being split to a further extent by the action of the pins.
Revolving at a higher speed, and in olose proximity to the first worker, is the first roller in the series which the cylinder passes after leaving the feed-rollers ; this is the " first stripper," whose function is to strip the worker, and return the material to the cylinder. No splitting or cutting of the fibre takes place in this case, the duty of the stripper being merely to return the fibre from the worker to the cylinder. The number of workers and strippers is dependent upon the size of the cylinder, which will permit more or less to be arranged around its circumference. This again depends upon the requirement of the work, or what is called the " fineness of the card." When the tow has passed the series of workers and strippers, it is received by a large roller, called the "first doffer," clothed similarly to the workers, but not accompanied by a stripper-roller. It
brings the tow to the front of the machine, at which position it is strip ped from it, by the rapid oscillating stripper-knife in its front, in the form of a sheet ; this is next divided into three portions, and each is passed between a pair of rollers, which calender and lay the fibre in the form of a sliver. Beneath the first doffer-roller, are one or two more of the same sort, having the same function, and stripped in the same manner, as the first. The slivers from all the doffers are received into a large can, and carried away to another machine, by which they are com bined into the form of a lap, to fit them for the " second carding." The laps from the first carding are then placed in the second, or finisher-card at the back, in the position occupied by the feed-apron of the first machine, but which does not appear in this case. The finisher-card is in principle precisely like the first, differing merely in details. Its pins are finer and shorter, and its rollers more numerous and smaller, by which means, the tow is subjected to more treatment than in the first instance.
In the treatment of superior tows, a combined machine, called the "breaker- and finisher-card," is often employed, in which one operation suffices to do all that is required. In this instance, the tow is evenly fed upon the revolving apron, passes through, and is delivered in an even sheet, which is divided into a number of slivers, one for each of the front conductors. They are next passed through the conductors of the bottom doffer, over a polished cast-iron plate, called the "sliver-plate," and into the back conductors of a "rotary-card drawing-head," which is attached to the machine, and so-called because the traverse of the gills is accomplished by rather different means than the spiral shafts of the ordinary drawing-frame. The sliver then passes through a very coarse open gill on a short draft, which prepares it for the first drawing-frame. The rotary head has one, two, or three rows of gills, according to requirement. Altogether, it is regarded by many persons as a questionable improvement, and its application is far from being general. When it is absent, the sliver is carried direct to a drawing-frame, in which it is worked up into sets.
Tow-carding engines should be carefully set, so as to stand perfectly level. Proper lubrication ought never to be neglected, and the drums and driving-pulleys should he as large as convenient, in order to give the fullest purchase, and so secure the most even and economical driving, without which the sliver will suffer in quality, and make inferior yarn.
Spinning.—Spinning is the concluding process of this division. In it, the material which has come through the successive stages is converted into yarn, and forms in this condition a merchantable article. In many cases, flax-spinning establishments have weaving branches in connection with them, in which case, their production of yarn may be consumed upon the premises. In others, it is sent upon the market, and forms the supply which is drawn upon by establishments at which weaving only is oarried on.