The economy effected by the invention will be easily seen from the following statement, which may be regarded as a fair average result of its application. Suppose a loom is required to be mounted for the production of a towel 40 in. long, and 90 picks to the inch. This, under the old system, would require 3690 cards, 600 long, the centre and border patterns being stamped on one card. If these patterns were on separate cards, as on a still older plan, 7830 cards would be required 300 long. By the improvement under notice, 600 cards 600 long will produce all the design. The expenditure on the first-mentioned system, requiring 3690 cards, would be as follows :—Cards, 51.18s.; punching the patterns, 5/. 5s.; hand, lls. 6d.; wire and wiring, 18s. 6d.; lacing, 1/. 7s. 14/. The improved form would be : for cards, 12s. 8d. ; punching, 18s. 8d.; band, 2s. 2d.; wire and wiring, 3s.; lacing, 4s. 6d. = 21. ls. In an economical point of view, this is of considerable importance in an establishment having a considerable number of loorns.
This heavy expenditure on the old plan has, however, led to the extensive adoption of the alternative metbod of changing the cards detailed above. But owing to the cost aud the loss of time during workiag hours, it is .questionable whether it is really of any considerable advantage. Also it may be remarked that any change in the length of the towel necessitates a corresponding change in the number of cards, which is a source of delay. The 600 cards on the improved plan weave any length required, and the change from the body to the border pattern is effected without stopping the loom. In fabrics having a medallion centre, on the plan generally in use, 1800 cards are required for border and filling in addition to the ordinary set, and these need to be changed six times during the weaving of each cloth. This improvement requires only an addition to the ordinary set of the actual cards used iu weaving the centre figure, whilst changing is altogether dispensed with. Its advantages will therefore be fully obvious.
In carpets such as Brussels, tapestry, and pile fabrics generally, the body, backing, or foundation forms the true fabric, with which the pile-threads are interwoven. The latter are usually of a different material, and are interwoven in such a manner as to form a terry, looped, or pile surface. The weaving of these articles differs only little from that of plain fabrics or those woven by the jacquard. All that is required in addition is mechanism by which the pile-threads can be formed into loops on the surface during the pi ocess of weaving. There are several plans of doing this, but the one in highest favour is that wherein wires are introduced into the " shed" or opening formed between the body and the pile-warp, and which, wben the threads of the latter have been woven down into the body-fabric, are withdrawn, leaving a line of loops across the width of the fabric. Previously to 1850, nearly all carpets of these kinds were woven by or on hand-looms. This was a laborious occupation, and the production of each weaver was a small length per week. There have been considerable improvements since the date mentioned, by which the quality has been improved and the production increased. There are yet in use in both this country and America a considerable number of hand-looms, chiefly employed with jacquard attachments on the production of ingrain and damask carpets.
Mechanicians in the field of carpet manufacture had a comparatively easy task before them. The power-loom with tbe jacquard attachmeot was ready to their hand iu a very perfect conditioa . All it required was that its different parts should be strengthened and adapted to withstand the shock of driving home the filling in a heavy fabric like a carpet. This was easily accomplished, as was the addition of a strong pacing or warp-delivery arrangement and taking-up motion. The principal part requiring to be invented, and which is peculiarly an adjunct of the pile-fabric loom, was an automatic method of inserting arid withdrawing the wires by which the loops of the pile are formed. Another important point was to combine this apparatus with the mechanism of the power-loom as employed for weaving either plain fabrics or those with jacquard patterns. After some difficulty, this was successfully accomplished, and since that time the carpet industry has rapidly extended in this couotry, and of late years also in America.
Figs. 1477, 1478,1479 illustrate the construction of the fabrics known as tapestry, Brussels, and velvet-pile carpets. The first is a longitudinal section of the tapestry carpet, with the shed open for the insertion of a looping wire. It will he observed that the warp consists of three distinct portions. The pile-warp a is usually composed of printed worsted yarns, the design being printed in such a manner that when woven and piled in the fabric, a pattern shall be the result. The next the body-warp b to', usually of linen or cotton yarna ; of late years, the latter have come to be preferred, as it is found from their greater pliability that they wear better than linen warps for backs. This warp binds the whole fabric together, being interwoven with the weft, the threada of which are seen in section at c, forming two series, one under and one over the third warp d. This warp is introduced to give thickness or substance to the fabric, and in tapestry is generally composed of some softly-apuo, cheap material which will allow the other portions to embed themselves in it, so that during wear the pile-threads will not easily allow themselves to be drawn from their position. The threads of this warp neither rise to the front nor descend to the back of the fabric ; being introduced only for the purpose before named, they are retained in the centre of the fabric. The threads of the pile-warp a are never taken below the filling-warp d, consequently they never appear at the back of the fabric, which fact explains the absence of coloured threads at the back of a tapestry carpet, by which inexpert people are best enabled to recognize its true texture. In weaving, the whole of the pile-threads are lifted and lowered at once ; when raised, it is for the purpose of admitting the introduction of a new wire as seen at e. When lowered, one portion of the body-warp b is raised to form a shed for the weft, which has the filling-warp d raised to form a different shed for its return. The course of each warp and its function in the construction of the web can easily be traced from the diagram. After a sufficient length of the fabric has been woven to prevent the tension on the pile-warp drawing down the loops, the wires are withdrawn, and are then ready for renewed use.