Page:Encyclopædia Britannica, Ninth Edition, v. 3.djvu/836

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814
BLEACHING
[cotton.

removed by an alteration in the construction of the cylinders, to prevent collapse, in case a vacuum were formed by the rapid condensation of the steam. A spiral rib or stay is made to run from end to end of the body of the cylinder, giving support uniformly the whole length, and serving at the same time as a screw to drive the condensed water, as the cylinder revolves, to one end, where it is ejected through a nozzle. The steam enters at a nozzle, from the framing which is cast hollow, and serves as a pipe to distribute the steam to all the cylin ders in the machine, while the framing on the other side serves in like manner to receive and discharge the

water.


FIG. 11. Damping-Machine.

FIG. 12. Elevation of Belt-Stretching Machine.

Damping.—From the drying cans the cloth is passed on to the damping-machine, where it is uniformly moistened by an exceedingly fine spray of water thrown upon it. The spray is thrown up by a circular brush, the tips of which are allowed to dip into water in a trough over which it revolves. Mather and Platt have introduced a manifest improvement on this plan by throwing the water in fine jets on the brush from a pipe which runs parallel with it. By this means the quantity of water and degree of moisture can be regulated with the utmost nicety. Fig. 11 shows the damping-machine in section as modified by Mather and Platt. a represents the circular brush revolv ing in a trough, and b is the pipe from which the water is squirted on the brush. The spray from the brush is confined by two sloping boards c, c, which work on quadrants, and the lever d raises or depresses the brush at pleasure. The course of the cloth over the machine is indicated by arrows, and after damping it is batched on an iron or wooden beam e, when it is ready for the process of beetling. When goods are to be finished of any parti cular width, they are at this stage breadthened by such an apparatus as the belt-stretching machine of Mather and Platt shown in elevation in fig. 12 and in plan in fig, 13. In this machine the full width of the cloth is obtained by the selvedges being held firmly by a belt and pulley on each side, the pulleys revolving at such an angle that the stretch on the cloth has to compensate for the difference in distance between these pulleys at A and B.


FIG. 13. Plan of Belt-Stretching Machine.


FIG. 14. Patterson s Patent Beetle.
Beetling.—The beetles ordinarily employed are a series

of long heavy wooden piles arranged in a frame. These piles are alternately raised and allowed to fall with their full weight against the beamed cloth by the revolution of a roller having a spiral series of notches, which catch a corresponding range of projections on the piles. The beam with the cloth is made to revolve gently by a ratchet motion as it is submitted to this hammering, which goes on for two or three hours. Recently Mr John Patterson of Belfast has patented and introduced a form of beetling- machine (fig. 1 4), which from its highly effective action is likely to come into very extensive use. The advantages claimed for his machine over the common beetle Mr Patterson thus states : " Heretofore, the beetling of textile fabrics has been done by means of beetles, or stampers, falling upon the fabric by the action of gravitation, each stamper or beetle falling 55 or 60 times per minute through a space of 13 to 15 inches. This rate of speed cannot be accelerated by gravitation, and the consequence has been that in order to increase the quantity of work done by the ordinary beetles, very bulky and massive machinery has been employed, requiring large and expensive buildings and driving gear. The new beetling-machine requires not

one-tenth of the space, very much lighter gearing, and