This form of condenser is in general use all over Europe, and, in the opinion of the best practical judges, is the most useful and perfect condensor in existence for all round work. In the American woollen trade, another kind is in use, called the roll-rub condensor ; but, as practical writers in the United States admit the superiority of the foregoing, it is not necessary to describe it.
Carding is probably the most important of all the processes of woollen manufacture. Nothing tends so much to success as its proper performance, and nothing so much militates against that 1454.
result as when it is badly done. The essentials of good carding are numerous, and include a proper arrangement of the machinery ; nice adjustment of the parts, especially the rollers ; careful clothing; good grinding ; flocking ; and correct relationships to each other of the speed of the cylinder, workers, strippers, fancy, and doffer. These are matters that call for attention before the commencement of work. During working, there are equally numerous conditions that require examination. Care should be taken not to overload the machinery with wool, which would result in defective work, as the cards would pass it on without sufficient treatment. The cards should never be permitted to fill up either with dirt or wool, as the material in process is thereby apt to be rolled. The technicalities of the treatment of wool and the management of the machinery are so numerous that to enter into detail upon them would extend this article to the compass of a volume.
Spinning.—Woollen yarn is usually spun upon the mule ; there are several continuous spinning machines, but though invention has been directed for a loug time to the construction of a good con tinuous spinning-flame, no such machine has yet achieved II. commercial success. The mule, as is well known, is an adaptation from the cotton trade, like the carding engine and many other machines in the various sections of the wool manufacture.
The woollen mule (Fig. 1455) is much simpler and has far fewer spindles than the cotton spinning mule. In general appearance it is much like the other, and consists of two carriages a a' mounted on wheels with the headstock b placed between them in the middle. Each carriage is
fitted with a number of spindles c, usually 500-600. The frame consists of the roller-beam and,creel carried upon the usual standards. The difference in the nature of the fibre of wool from that of cotton precludes the use of drawing-rollers, as in cotton-spinning. The woollen mule is therefore only furnished with one row of fluted rollers, provided with a corresponding row of top rollers d. The condenser-bobbins being supplied to the frame, the threads are drawn off, passed between the rollers, and attached to the spindles. The mule is then ready for commencing work. Simul taneously the spindles begin to slowly revolve, the carriage to draw out from the roller-beam, and the rollers to deliver the condenser-threads. When the carriage has traversed about half its journey outward, the rollers cease to deliver the material. The carriage proceeds on its course, imd the spindles continue revolving, by which means the condensor-threads delivered from the rollers are gradually attenuated, until, by the time the carriage has reached the extremity of its traverse, this is completed. The thread, however, as yet is only soft and loose, and must be rendered com paratively firm and strong. In order to accomplish this, the revolution of the spindles is greatly accelerated, and the thread rapidly twisted. This twisting takes up the length of the extended thread, in order to allow for which the carriage is made to move in a few inches as the twisting proceeds. When this is completed, the spindles are automatically arrested, and for two or three turns have their movement reversed to form the "backing-off process," as the unwinding of the several turns of yarn upon the spindle-tope is called. This being performed, and the slack simultaneously taken up by the "falters," the carriage proceeds inwards, winding the threads upon the cops until the spun portion is all thus diaposed of. The proeese then recommences, and is repeated in all its details, recurring until the set task is accompliehed. When the spindles are filled, they aro " doffed," that is, cleared, and a new set is begun.