In the operation of the loom, when one bcddle is raised every second thread in the warp is also raised, while the remaining threads are depressed; and this is called shedding the warp N%'hen the warp threads are thus parted there is left a small opening or shed between the threads directly in front of the reed, and it is through this opening that the weaver drives hi shuttle to and fro, from side to side. The shuttle, which is hollow in the middle, con tains the weft-thread wound around a bobbin or pier*, and as the shuttle is shot across the web this weft-thread unwinds itself. When the thread is thus introdnced it is necessary to bring it to its place in the fabric. This is accom plished by means of the ley or batten, sus pended from a pivot at the top of the loon, mewing backward and forward like a pewit, turn by an attachment of vertical rods at cac1 tide railed the swords. The teeth of the ref. are thus swung forcibly against the newly lai, weft thread driving it solidly to its place in the cloth. The other treadle is then pressed down, raising the other heddle and, with it, the alternate warp threads, thus forming another shed, in which the threads which were the floor of the first shed are the roof of the second. Through this new shed the shuttle is thrown on its return journey. This throwing of the shuttle is termed 'picking' and each traverse of the is called a 'pick.' The travel of the shuttle is accomplished by means of a Y-shaped handle, to the arms of which are attached two strings which lead one to each of the shuttle boxes at the ends of the Icy. A quick jerk upon the string sends the shuttle flying out of its box through the shed of warp threads and into the lox at the opposite end of the Icy. Thus the weaving proceeds, the ley being swung forward, driving up the new weft thread, after each pick of the shuttle. Occasionally, as the web of finished cloth increases, the loom is stopped, and the cloth is wound up around the cloth-beam, another stretch of warp being unwound from the warp-beam; and this suc cession of operations continues until the entire length of the warp has been woven into cloth.
Weaves.— There are three fundamental methods or plans of interlacing the warp and weft threads in weaving; (1) plain weave; (2) twill weave; and (3) sateen, or satin weave. All woven cloths may be referred to one or another of these three primary plans or of a combination of two or more of them — in which case the texture is called •combination weave.• By far the larger part of all woven fabrics is produced by the plain weave method, but these cloths are varied in many ways — by modifica tions of the relative sires of the warp and weft threads, by manipulations of the heddles, and to an unlimited degree as to the color and design by the use of self-colored and parti colored threads in both weft and warp.
Plain Weave.— In plain weave the threads are made to interlace alternately; and, if the warp and weft threads are of the same diameter, and there are an equal number of each to the inch, they bend around one another to about the same degree, and thus form a plain fiat uniform cloth, in which the warp and weft threads appear equally on the surface. With this weave
are produced the finest cambrics and muslins, and the heaviest woolen blankets—and the numberless other fabrics of similar texture lying between these two extremes.
A diagram of the interlacing of plain weave fabrics is shown in Fig. 2, the threads A, A representing a section of the warp, and the continuous cross-thread B. B representing the weft. In actual weaving the warp threads would lie close together, usually from 16 to 64 to the inch, and each pick of the weft would be driven tip snugly to the one preceding by a blow of the reed. In order that the weaver may know what style of cloth he is to produce, a plan or pattern is drawn for him by the de signer on paper ruled in squares; the latter being marked in some way to indicate the position the thread represented will occupy in the finished cloth. The rows of squares running vertically indicate the warp, and those horizon tally the weft. As only the warp threads are raised and lowered by the heddles, the pattern is made to indicate these movements by coloring the squares.
Ordinarily (though the exact reverse is sometimes encountered), a blackened square shows that that section of the warp is de pressed below the weft thread on that pick. It is also customary to show the threading of the heddles above (or below) the pattern—as shown in the figure. The two heavy horizontal lines indicate the bars of the two heddles used in plain weaving; the upright lines leading to the heddle bars from the pattern indicate the method of threading each strand of the warp.
Fig. 3 shows a diagram of the arrangement made in several ways; for example, by taking in two or more threads of the warp with each pick of the weft, thus extending the ex posure of the weft from side to side. or as this form of pattern is designated, in the 'hori zontal' form. Or two or more threads of the warp may be passed under by the weft in con secutive picks without change of the heddles, thus exposing more of the warp than is usual in simple plain weave, thus forming a •verti cal* pattern. Plans for both these patterns are shown in Fig. 4. Such modificaticas may be of levers where both the rising and sinking of the warp threads are employed in producing the shed. The short horizontal levers are so tied to the long ones that when one of the latter is depressed by stepping upon a treadle, thus rais ing one of the heddles, all of the other heddles (three in this case) are pulled down, producing the double movement shed shown in profile in Fig. 1.
Modifications of the plain weave may be uniform, or they may be uneven in design. that is, the same number of threads may be taken in at each stitch, or there may be a con stant variation, as l-and-3,.1-and-3, and so on. If the same number (more than one) are taken both vertically and horizontally the `basket weave' is produced. Plans tor these also are shown in Fig. 4.