WEAVING, the art by which threads or yarns of any substance arc interlaced so as to form a continuous web. It is perhaps the most ancient of the manufacturing arts, for clothing was always a first necessity of mankind. The methods by which weaving is now accomplished: have been explained under loom (q.v.); it therefore only remains to describe the variations which may be effected by ingenious applications of the powers of the loom; and as these are almost endless, some of the more common and easily understood will be chosen. The simplest form of weaving is that employed in making the mats of uncivilized nations. These consist of single untwisted fibers, usually vege. table, arranged side by side to the width required, and of the length of the fibers them selves, which are tied at each end to a stick, which is so fixed as to keep the fiber straight, and on the same plane. Then the weaver lifts up every other of these longi tudinal threads, and passes under it a transverse one, which he first attaches by tying or twisting to the outermost fiber of the side he commences with, and afterward in the same way to that ou the other side, when it has passed through the whole series. The acquisition of the art of spinning threads of any i length a th en bles more advanced nations to give great length to the warp, or series of threads which are first arranged, and to pass the weft or transverse thread backward and forward by means of a shuttle, without the necessity of fixing at the sides. The mechanical appliances already described under LOOM aid these operations to an amazing extent. That kind of weaving which consists of passing the weft alternately over and under each thread of thm arpiscat called the p etin weaving; but if the weaver takes up first one and then two threads alternately and passes the weft under them for the first shoot of his shuttle, t o raises he wp series, _ ses ose which were left down before for the second shoot, he produces a cloth with a very different appearance, called twill (q.v.), many varieties of which may be produced by varying the numbers missed or taken up—as, for example, one and three, instead of one and two.
There are few arts which require more patience or skill than weaving. As many as from one to two thousand threads often constitute the warp; and these threads may be so varied in quality (see YARN) as to produce many varieties of fabric. From that cause alone there are almost infinite variations. Many may be produced by the order in which the threads are lifted for the passage of the weft—that of itself can also vary as much or more in its quality and other circumstances, so that the inventive genius of the weaver finds incessant opportunities for its display, and nice arithmetical calculations are required in estimating and allotting the numerous threads to the endless variety of patterns which are constantly passing through the looms. A really practical knowledge of weaving can only be obtained by working with looms, and studying such technical treatises as Watson's Theory and Praelke of the Art of Wearing, and some of the elabor ate treatises by the French weavers.
There is no branch of manufacture in which inventions and improvements are more rapidly succeeding each other than in weaving; but, as a rule, they are of minor impor tance, and rarely affect the general principles of the process. In 1867, however, the
novelty of convex weaving by machinery was introduced, and although only at present applied to ladies' stays, seems to promise a wide application to clothing generally, and many other purposes.
Out of the numerous attempts that have been made during the last ten years to weave by machinery a convex surface, such as is required in several articles of clothing, hardly one, up to the present time, has succeeded. This failure has been owing partly to • deficiencies in the various inventions of this kind, and partly to the costliness of carry ing them out. At last, after long and patient trials, a patent convex weaving-loom has been invented that not only answers all the purposes of the hand loom, hitherto exclu sively used, but also possesses the advantage, which is absolutely necessary in a country where labor is scarce, of doing ten times the amount of work in the same space of time. With the hand-loom, one man can make, at the very utmost, only four pair of stays in a day, whereas the new-invented convex weaving machine turns out 40 pair daily. The superior lightness and flexibility of woven stays, and their perfect freedom from hard seams, have increased to a very large extent the demand for this class of goods. Up to the present moment, band-labor alone has been employed in France and Wiirtemberg, two countries where they have been most extensively manufactured. In the United States, however, where the high wages for hand-labor have necessitated the most exten sive use of machinery, this system could not be adopted.with any possibility of pecuni ary success; and, in consequence of this fact, a loom for weaving of stays and other convex goods had to be invented. This loom, which was constructed under the super intendence of M. Opper, for the convex weaving company in New York, does the work automatically and to perfection.
The principle of a constant length of travel for the shuttle was adopted for the sake of simplicity; but, as it is necessary, in weaving the gores, that the weft-thread should pass through only a part of the breadth of the warp, the Jacquard has been employed for the purpose of taking up the portion of the warp required to be woven in that part. It is impossible by mere verbal description to give any adequate notion of this ingenious machine without seeing it in operation.
Bonelli's loom is an ingenious attempt to substitute for the costly perforated cards of a Jacquard loom an endless band of paper covered with tinfoil, on which the required pattern is traced with a varnish, rendering the parts thus covered non-conducting. This band of paper passes under a series of thin metallic teeth, each connected with a small electromagnet, and these magnets act on a series of small pistons. According as these teeth come in contact with the metallic surface or the varnish, so is a series of holes in a perforated phite closed or opened when an, electric current is passing. The perfora tions in the plate correspond to the punched holes in the cards of a Jacquard, and act in the same way upon its needles. See JACQUARD LOOM. Bonelli's loom, though it was perfect enough far practical work in 1860, has not yet been brought into use. It is fully described in the Society of Arta' Journal, Jan. 60860.