When tho warp is completed on the warping-mill, the warper takes It off and winds it on a stick into a ball, preparatory to the process of beaming, or winding it on the beam of the loom. The threads, in this latter process, are wound as evenly as possible on the beam; a sepa rator, ravel, or comb being used to lay them parallel, and to spread them out to about the intended width of the cloth. Arrangements are then made for drawing, or attaching the warp-threads individually to certain mechanism of the loom. This we may illustrate by jig. 2, reprteenting the common loom In its nimplest state. The yarn-beam will show more clearly the mode in which the weft is wound round the spindle or pirn of the shuttle, and the arrangement for driving the shuttle into the open shed of the web. The spindle of the shuttle con tains enough weft for several shoots or throws ; the weft unwinding as the shuttle travels along, and forming the selvage of the cloth when the shuttle returns in the opposite direction.
In cotton and some other fabrics, the warp-yarns must be dressed as the weaver proceeds, that is, rubbed over with some kind of vegetable mucilage, such as paste or size, for the purpose of giving them tenacity, of diminishing friction by smoothing down the little hairy filaments of the yarn, and of imparting a smoothness or gloss. In hand-weaving, the weaver suspends his operations from time to Limo, in order to apply dressing to his warp. Ile first applies a kind of comb to the warp, to clear away knots and burrs ; then lays ou the paste with a brush ; and lastly dries the paste by a current of air excited by a largo fan. Tho more modern and complete dressing-machine wo shall have to notice in connection with power-weaving.
In weaving plain silks, calicoes, and other webs of moderate width, there are two leaves of heddles and two treadles, for dividing the warp into two parcels. In weaving broader webs, such as floor-cloth canvas, the heddles and treadles are equally simple, but more power and dex terity are necessary in throwing the shuttle, since the width of the web is sometimes as much as eight yards. In weaving very narrow webs, such as ribbons, galloons, &o., there would bo a waste of power and of time if only one shuttle were thrown across a distance of two or three inches at each movement ; and there has consequently been devised a kind of loom called the engine-loom, in which several shuttles work several webs at one time in each machine ; this has been explained in Itinnos. Various details concerning plain woven goods will be found under COTTON ; LtNEN ; MUSLIN ; SILK ; WOOLLEN.
Petterseirearine.—The number of wovcu webs which can come under the designation of plain-weaving is much smaller than that of those now to be considered. Whenever the warp and weft are of the same colour, and intersect each other in regular order, so as to produce a uniform surface totally divested of pattern, we may deem that plain wearing; but every day'a experience shows that pattern, of some kind or other, hut more prevailing characteristic of woven fabrics.
In the first place we may take the case in which all the threads of the warp are of one colour, and all those of the weft another colour : this prd duces the peculiar effect called shot patterns, but involves no new arrange ments as to weaving. Next come the two varieties known respectively as stripes and checks. A stripe is a pattern in which parallel lines run either along or across the warp ; while a check is an alternation of rectangles like a chess-board, or, more properly, like the varieties of Scotch plaid. The production of a stripe depends either upon the warper or the weaver ; the production of a check depends upon both.
If the stripes are of different colours, and extend lengthwise of the cloth, then the warper so disposes the threads of his warp that the two colours shall succeed each other at regular intervals ; but if the stripes are of the same colour, but of different quality as to fineness, then the warper uses two qualities of warp in alternate succession. If the stripes extend across the cloth, the warper arranges his threads as for plain-weaving ; but the weaver uses two or more shuttles, carrying two or more coloured wefts, and throws the shuttles at regular intervals in succession. If a check is to be produced, the warper first produces his alternation of colours in the warp, and the weaver then throws in wefts of different colours by using two or more shuttles, so that the interlacing of the long stripes with the cross-stripes produces the check, the pattern of which depends on the comparative width of the various stripes. The manner of using the combined shuttles is described under CuECK.
The next to be noticed is the production of the twill, a very exten sively adopted variety of woven work, since it comprises satin, bomba zecn, kerseymere, and numerous other kinds. In the twill, the weft threads do not pass over and under the warp-threads in regular /RIC cession, but pass over one and under two, over one and under three, or over one and under four, six, &c., according to the kind of twill. The effect of this is to produce a kind of diagonal ribbed appearance,on one side of the cloth, and a smooth and glossy appearance on the other, according as the one thread is crossed above or below by the weft. Pig. 4 will assist our comprehension of this point. If we suppose the round dots to be sections of successive warp-threads, and the white double line to be one thread of weft, we shall see that the weft passes over four, under one, over four ; then under four, aver one, under four ; and if the specimen were continued, we should see that these cycles of changes succeed each other in regular order. This arrange ment furnishes the twill for some particular varieties of cloth ; and the weaver has thus a kind of numerical formula for diaper, dimity, dor nock, damask, bombazecn, satin, kerseymere, &c.; each one having a certain order of succession in which the weft crosses the warp. [Bois EAZEEN ; DAMASK; DIAPER.] Now in order to allow-the weft to pass under four or more threads at once, some mechanism must be devised for elevating all those four at one movement, or keeping them stationary while every fourth thread is depressed. If the weft always passed under tho same four threads, no cloth would be produced, for no reticulation would be made ; but the groups of four passed under by one waft-shoot are not the same as those crossed at the next following shoot. Hence more than two leaves of heddles are required, and more than two treadles to work them. There must, in such a case as we have above supposed, be five leaves of beadles, to each of which every fifth warp-thread is attached ; and to each of these leaves a treadle is appropriated ; so that when one treadle is pressed down, one-fifth of the warp-threads becomes drawn out of the horizontal plane ; when another treadle is depressed, another fifth is affected ; and so on. The weaver, by the management of his treadles, has the power of raising or depressing four-fifths of his warp threads, in groups of four each, leaving every fifth thread stationary; and in this state of things ho throws his shuttle. By various combina tions among his five treadles, he can produce many varieties of move ment, which give rise to different kinds of twill.