Page:The New International Encyclopædia 1st ed. v. 20.djvu/461

* WEAVING. 383 WEAVING. the loom-reed — usually before the warp is plneed in the lomii — and after l)ein;,' stretehed tifjlit from the warij-beani placed at the back to the clolh- roll in front are ready to be woven. There are three underlying principle move- ments in the weaving of textile fabrics: First, the 'forming of the shed' is accomplished in various ways, but results in separating the warp- threads into two or more series which may be raised or depressed, leaving a horizontal space through which the tilling is 'picked,' either by the hand of the weaver or the mechanism of the loom, completing the second movement; by the third movement the thread left in the shed is 'beaten up' by the action of the lathe or batten which carries the reed. The process of weaving is simply a continual repetition of these three movements in the order named. The simplest form of weaving was that em- ployed in making the mats of uncivilized nations. These consisted of single untwisted ri)>res, iisual- ly vegetable, arranged side by side to the re- quired width, the length being governed by the length of the fibres themselves; these were tied at each end to a stick so arranged that the fibres were kept straight, and on the same jdane. The weaver then lifted up every other of these longi- tudinal threads and passed under them a trans- verse thread which he first attaelied by tying or twisting to the outermost fibre of the side commenced with and afterwards in the same way to that on the other after it had been passed through the whole series. The acquisition of the art of spinning threads of any length enabled more advanced nations to give greater length to the warp threads, wliieh after being arranged in parallel lines between two beams and held in po- sition by parallel tree-trunks, to which they were secured, were ready for the weft-yarn, w-hich, secured to a stick or threaded into a needle, was woven in and out of the warp threads by hand, as in the more primitive basket-weav- ing. The development of the modern loom and its mechanism is described in detail in the ar- ticle Loom. Up to the end of the eighteenth century weav- ing was performed wholly by hand-looms; these were usually operated by the weavers in their own homes, and the fabrics produced were usual- ly made from yarns spun by the weaver or some member of the family. About the middle of the eighteenth century machinery for spinning yarns began to lie improved so that there came a de- mand for an improved loom : the result was the production of a power-loom in 1785 by Dr. Ed- mund Cartwright, which came into successful operation in weaving-sheds or factories in the early part of the nineteenth century. The de- velopment of the industry has been attended by gome of the most wonderful mechanical inven- tions. The result is the automatic production by machinery of fabrics rivaling if not surpass- ing the most elaborate and costly made by hand with far greater rapidity and a greater degree of perfection. Weaves. While there are innumerable ar- rangements, called iceaves. for the interlacing of the warp and filling threads in weaving various textile fabrics, these arrangements are all based on three primary weaves, illustrated in Figs. 1, ^, and 3, technically called the plain, ticill, ami FlO. 1. PLAIN WEA^X. saliii weaves, respectively. Practically all other arrangements are made by variations or combina- tions of these three. In Figs. 1, 2, and 3, the horizontal lines at A represent the hiom-harncss with the disposi- tion of the warp threads on same: the wrare is shov.n at B written out on squared design or cross-section paper, each section rejiresenting the crossing of a warp ami filling thread and the X marks showing that the warp is above the filling at' the point they a]ipear: the blank sec- tions show that the fill- ing is above the warp : the threads as inter- laced are shown at C and a section of the fabric cut through the warp is shown at D. The plain weave (Fig. 1 ) is the simplest form of we;iving, requiring but two different move- nu'uts of the warp threads. Four repeats of the weave in warp and filling are shown. From an examination of the several diagrams it will be seen that the movements of threads marked 1 are identical and of threads marked 2, while all alike, are exactlj* opposite to the movement of the former; this makes it pos- sible to arrange the warp for the loom on the harness frames, as at A, and by raising No. 1 and depressing No. 2 the shed is formed while the first pick, or shot, of the filling is passed through, then harness No. 1 is depressed and No. 2 raised and the second filling thread is passed through the new shed ; the third shed is like the first, the fourth like the second, and the weave repeated forms the fabric with the plain weave. Patterns in this weave can only be produced by the use of threads of diflerent colors or material. It is not only the simplest but the firmest and strongest of weaves. The ticill iceave. as illustrated in Fig. 2 by one of the simplest forms, is a weave in which the filling threads pass over or under two of more adjacent warp threads at a time, at least once in a repeat, each of the picks being alike ex- cept that each is stepped one thread to the right or the left of the one preceding it. The simplest twills may be woven on three harness and are technically 'one up and two down,' i-,, or 'two up and one down,' ij, twills, the former being a 4 -f- T~ ' T •' 3 XX 2 XX X X X X 4 X X X X 3 XX X X 1 X X X X 12 34 12 3 4 Q.I "^ax);;g^iys>^5^ Fig. 2. TWILL WEAVE.