Beneath these three cisterns, on the ground floor, are six stone cisterns : two for holding a solu tion of hydrochloric (muriatic) acid, two for sulphuric acid (vitriol), and two for a solution of bleaching powder (chemick). These cisterns are made of stone slabs, bolted together with iron rods on the outside. The joints of the hydrochloric acid cisterns axe rnade tight by bands of indiarubber, let into grooves cut in the edges of the slabs; the joints of the sulphuric acid cistern are made with molten lead, and those of the chemick cistern with Portland cement. These cisterns are connected by pipes (iron for the chemick, lead for the acids) with the chemicking and soudng machines, so that no carrying of the solutions is needed.
Fig. 347 shows the arrangement of a pair of Barlow's high-pressure bleaching kiers, one of which is given in section. a b are the kiers, of strong boiler-plate iron ; g is the faLse bottom, con sisting of smooth water-worn boulder stones, or a cast-iron grating, on which the pieces to be boiled ere laid ; d is the distributor, of wrought iron, acting also as a stay pipe ; the upper portion is perforated and dosed by a stop some distance from the bottom ; the block lt at the bottom is pigeon holed to allow liquor to pass from the kier ; above, the distributor is connected with the tap t (an ordinary two-way tap), by which steam is admitted from the main pipe m, and the reversing of which shuts off the steam communication and admits the liquor as it is expelled from the adjoining kier ; p p is the pipe connecting the top of the kier a with the bottom of kier b, and q q is the pipe connecting the top of kier b with the bottom of kier a ; s s are steam pipes from the main m ; 1/ are the pipes and taps through which the liquors are introduced ; o o are the manholes, through which the goods are entered and removed, and which can be closed by an iron plate held with t'we cross bars and screwbolts ; tv to are the draw-off taps connected with the pipes p and q, and which can be worked from the stage at c c in emptying the kicrs of spent liquor, &c. ; i are glass gauges, by which it is seen when the liquor has passed entirely from one kier to the other ; u u are short iron columns to support the kiers. The dimensions of these kiers are various. To hold each about 6000 lb. of cloth, the dimensions may be about the following : height, 10i- ft. at the side, with IO in. bulge at each end, diameter, 7 ft. The distributors give an equal circulation of liquor or
steam from the centre of the kiers through the goods all around, and prevent the goods from being pressed down into a compact mass, to which they are liable if the steam enters directly from the top ; on the contrary, by this distribution, die pieces are kept rather in an open and loose condi tion, and the circulation of the liquors is thereby accelerated.
Without entering imto every variety of detail which the fancy of each bleacher suggests, it will be sufficient to continue the description of the routine which the pieces to be madder-bleached have to pass through after singeing, premising that Barlow's kiers are used.
The following is a summary of the operations :— 1. Wash from the singe.
2. Lime into Ider, boil with lime, and wash.
3. Sour and wash into kier.
4. Boil with resin soap, then with soda ash, and wash.
5. Chemick.
6. Sour, wash, squeeze and dry.
Washing.—The pieces are run direct from the usually adjacent singeing house into the bleaching house ; guided, by means of the " pot-eyes," through the grey washing machine ; and are piled on the floor. By this operation, the pieces, which till now have been in the open width, assume the rope or chain form, which they continue to have throughout the whole of the succeeding operations, till opened and dried. The friction of the squeezing bowls in the washing machine is sufficient to draw the pieces from a considerable distance, obviating the necessity of carrying them. A boy folds or plaits down the pieces ou the floor, by means of a short stick, as they come from the washing machine. It is usual to allow them to lie thus in the pile over night to soften, though this is not absolutely necessary.
Limeing.—Frorn the pile, the pieces are run through milk of lime contained in the " limeing machine " direct into the kier, being drawn by the winches immediately above the latter. Boys enter the kier, and continuo to plait down the pieces with a short stick and to press them down with the feet till the kier is filled. The whole of the cloth in a kier is generally in two lengths, say 6000 lb. cloth, equal to about 1000 to 1800 pieces of 25 yds. each ; by this arrangement, the kier is more quickly filled and emptied than if the pieces were in a single length. This plan of running two lengths of pieces at the same time is usual in working the washing and other machines.