Page:Encyclopædia Britannica, Ninth Edition, v. 3.djvu/834

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Washing.—The cloth as it issues from the kiers is found to have assumed a very dirty brown aspect. Formerly, the apparatus used for washing was either the wash-stocks or the dash-wheel, to which allusion has already been made. The machine now generally employed is represented in section in fig. 9. It consists of a pair of wooden bowls or cylinders a and b, about 9 feet long, mounted in a strong framework, and arranged to press against each other in their revolution. Plane tree is the wood most suitable for making these bowls. Running underneath the whole length of the bowls is a box or trough c filled with water, near the bottom of which a rectangular roller d is fixed. The water in the box is constantly renewed during washing operations by a current flowing in at the middle and escaping at each end. Two chains of cloth are washed in this machine at the same time, one being introduced at each extremity of the roller. The cloth passes down into the water under the roller d and up to the wooden bowls, between which it is caught and nipped, and down again into the water, working its way in a spiral manner from the end to the centre of the machine, passing nine times through the water and between the bowls in its progress. Its course inwards is guided by a strong wooden rail, from which pegs project, arranged according to the number of turns to be given to the cloth. In the centre part of the upper bowl there is a lapping of cotton rope, which projects a little above the surface of the wood, and serves to give the cloth, as it finally issues from the machine, a much stronger squeeze than it would obtain between the long even bowls, and thereby expels a large proportion of mois ture. As the cloth travels inwards towards the centre of the trough, while the flow of water is outward to escape at each end, the cloth on each revolution is meeting water more nearly pure, till just at the point where it issues from the trough for the last time, the clean water entering the trough is powerfully spurted upon it, thus giving it a thorough rinse before it is finally squeezed. It is usual tc pass the cloth from the lime boil either through a pair of such washing-machines, or twice through the same, in ordei to expel the last trace of calcareous soap and uncombineJ lime from the texture. Fia. 9. -Section of Washing-Machine. In addition to this machine various other devices have from time to time been proposed and introduced to perform the important operations of washing. Among these the continuous washer of Mr Henry Bridson of Bolton-le- Moors, Lancashire, patented in 1852, is deserving of notice as a simple and efficient washing-machine. Mr Bridson s washer consists of an oblong tank or trough of cast-iron which, in use, is kept about half filled with water. Within this tank, just dipping into the water, two cross shafts are fixed, which are geared to revolve in the same direction by spur-gearing mounted outside the trough. Each shaft carries a pair of discs of large diameter, and between the discs of the two shafts a pair of bars placed diametrically opposite each other are mounted. These bars form flat winces or revolving frames, by the revolu tion of which the fabric is not only carried forward, but is in its progress caused to strike with great violence against the surface of the water. The intermittent flapping and shaking motion thus communicated to the material has a powerful effect in detaching adhering impurities from the cloth. Another form of washing-machine in use in Lancashire consists of a row of eight vats or troughs arranged in an ascending series, so that the overflow of water from the highest or last runs into the second highest, and so downwards till it escapes from the lowest or first. The cloth enters at the lowest trough, and is carried by guide-rollers up and down through the entire series, issuing at the top between a pair of squeezing rollers.

Gray Sour.—From the washing-machine the chain of cloth is passed through a pair of squeezers, by which a large proportion of moisture is expelled. The operation of souring, which comes next, is performed in an apparatus of the same construction as the washing-machine, the trough under which contains the souring liquor. For white bleaching a solution of hydrochloric acid of a strength of 2 Twaddle (sp. gr. 1010) is used, and for print bleaching the solution is made up to 4 Tw. Through this the cloth is passed up and down twice by the revolution of the bowis, and piled up in the sour in stillages for some hours. The object of the souring is to dissolve any traces of free lime which may have been left in the washing, and to decompose the calcareous soap.

Second Boil.—After having lain in the sour for a sufficient length of time the cloth is passed through squeezers to expel as much as possible of the acid, and again washed in the machine. It is next passed into a kier or set of kiers, precisely as after liming, for the second boil, which in the 