Page:Encyclopædia Britannica, Ninth Edition, v. 3.djvu/837

.] instead of making 60 blows per minv.te, each beetle makes from 420 to 500 blows per minute. The blows are not by the action of gravitation, but are actuated by a series of cranks cut upon a solid steel shaft. There are connecting rods from the steel cranks to semicircular springs. The beetles are attached to, or suspended between, the points of the semicircular springs by means of leather straps. &quot;When the crank shaft is set in motion the beetles are snatched up in regular sequence by the upward motion of the cranks, and the springs are compressed by the weight of the beetles, as in fig. 15, and by the combined upward motion of the cranks and the springs the beetle is thrown upwards with great impetus. The upward motion is stopped as the cranks pass the top centres, and the beetles are thus met by the springs and thrown violently into them, causing them to be again compressed, as in fig. 16. When by the downward motion of the cranks the springs are allowed to throw the beetles on the cloth beam, a rapid forcible whipping blow is imparted to the cloth, which does not cut or injure it in the manner often done by the slow dropping blows of the ordinary beetles. The weight of the blows can be instantly varied by varying the speed of the crank shaft, from the slightest touch to the heaviest penetrating blow. It is found that twice or thrice the number of folds of cloth can be beetled effectively on the cloth beams more than can be done on ordinary beetles, that is, instead of 200 folds on the beam, 400 or 600 folds can be equally well beetled on the new machine.&quot; Fio. 15 FIG. 16. Hammers of Patterson s Beetle.

Calendering.—When it is desired to finish cloth with a stiff or with a glazed finish, instead of being submitted to the operation of beetling, it is finished in the calender. The calender, as its name KvXiv8po9 implies, is a series of cylinders mounted above each other in a strong frame work. The number of cylinders and the material of which they are constructed vary. In some only three cylinders or bowls are employed, and in others they are four or five. One or two of the bowls are made of metal, and two or three are either of wood, of condensed cotton, or of paper, and they must always be turned with great accuracy and be free from all warping. Cylinders of paper or con densed cotton have a very smooth surface and a consider able amount of elasticity. Between these cylinders the cloth as it comes from the damping-machine is passed, and twice, thrice, or four times, according to the construction of the calender, it is powerfully pressed. The pressure gives the cloth a very even surface, condensing the fibres, and produces a shining lustre. When the cloth is submitted to friction, as well as to pressure in a heated calender, a glazed finish is produced. The f rictional effect is produced by the cylinders being geared to move at different rates of rapidity, so that in their revolution they rub over the sur faces of each other in addition to communicating pressure. Fig. 17 shows a finishing or friction calender in section. The metal cylinder a is made hollow so that it may be heated by the introduction of steam or gas, b and d are of compressed cotton or paper of the same diameter as a, and c is a smaller metal cylinder. The pressure of the cylinders is regulated by means of the screw e, and the compound lever/, which is adjusted by the double screw on the con necting rod at fj. The cloth enters over stretching rails and rollers, passes through the calender in the manner indicated by the arrows, and is batched on roller h. FIG. 17. Section of Calender.

Elastic Finish.—This particular kind of finish is applied to muslins and similar thin fabrics, and has to be done in highly-heated apartments called stentering stoves. Formerly the work was entirely done by manual labour, and con sisted in holding the fabric by the selvedges, and pulling it forward and backward while it was drying in the heated air. In this way the threads were made to rub against each other, and the cloth was thus deprived of the hard, stiff board-like appearance it would have possessed if left motionless when drying. Mr Ridgway Bridson was the first who introduced a machine which successfully supplanted hand labour in producing the elastic finish in muslins. His stentering frame is thus described : Two horizontal rails or frames extend side by side the whole length of the machine, carrying at each end a large wheel or pulley, with small pins fixed at equal distances in its periphery. These pins pass through corresponding holes in an endless band which passes round the pulleys. On the surface of the endless bands are fastened very fine needle or tenter points to hold the selvedges of the fabric as it passes through the machine. The horizontal rails can be moved away from each other laterally, so as to stretch the fabric breadthwise. The rails are of equal length with the fabric to be treated, vrhich is fastened by the selvedges at one end to the centre pins, and the pulleys being set in motion, the entire piece is carried on and stretched out over the machine, and the rails are then moved outwards to breadthen the fabric. The elastic finish is given by communicating alternate vibrating motions to the two rails, by which a diagonal stretching is given to the muslin while in the process of drying. At the conclusion of any of these various finishing- processes, the goods are folded either in a plaiting-machine or by girls hooking plaits of definite length by the selvedges on steel spikes. The end of each separate piece is then stamped with some device or motto intended to serve as a trade-mark. After the goods have been regularly folded, they are placed piece by piece, separated by sheets of 