The Jacquard cards are placed on the machine at _B´_, and move in rotation under needle, _Z_. The movement of the cards must be so regulated that, notwithstanding the want of uniformity in the arrangement of the holes, each hole in turn must come directly under the lacing needles.
The lacing of the cards is produced as follows: After the cards have moved one hole, the needles, _Z_, lower to _P´_, Fig. 43, making the shed. The shuttles move with their points under the thread thus lowered by the needle, and pass clear through the loop. After the needles rise, they will in turn tighten the loop, the shuttles return to their original position, and the work repeats.
This method of lacing Jacquard cards has the disadvantage of compelling the machine to be stopped oftener than if using the two-needle system (Fig. 32), as the shuttles will only hold a small quantity of lacing twine.
Designers for Jacquard work, in addition to being good draughtsmen, must be thoroughly acquainted with the three systems of weaves: plain, twills and satins, and their sub-divisions; also with the structure of double cloth, three-ply cloth, four-ply cloth, etc. He must know the influence of the texture upon the weaves and the fabric; the arrangement of the threads in the dents of the reed; the different systems of tying-up the Jacquard harness; and the stamping of the Jacquard cards for the various kinds of textile fabrics.
Squared Designing Paper for the Different Textile Fabrics Executed on the Jacquard Machine.
The classifying of the [O] designing paper is done by enclosing a number of small rectangles, horizontal and vertical, within a certain distance by a heavy line. Such enclosures are known in practice as “squares.” The spaces between the vertical lines indicate the warp-threads, and those between the horizontal lines the filling threads. As a rule the warp dimension is indicated first; and a design paper having five rectangles vertical with ten horizontal, is variously read and indicated as 5 by 10, 5 × 10, or 5/10.
Figs. 46 to 68 represent some of the styles of [O] designing paper most frequently used. The size of the square may vary in each kind of paper, and must be selected according to the fabric to be sketched. For example: There are three styles of 8 × 8 [O] designing paper in general use: One forming 1/2 inch heavy squares, (Fig. 48), one forming 3/4 inch heavy squares, (Fig. 64), and the other forming 1 inch heavy squares. These sizes may still be varied.
