This is a very good motion, perhaps could not be surpassed for the purpose, but, as I said before, has the objection which all similar contrivances for the purpose must have—viz., causing too much vibration in the harness. All the cords constantly dancing up and down causes an unsteadiness and swinging that is not to be found in the ordinary jacquard harness. These machines have sixteen rows of needles in them, which are much closer set together than those in this country, and give a large number of hooks in a small-sized machine, which is a great advantage when extensive patterns are required. In this machine the half-card contains 440 holes, or 880 holes to the full or double card. The pitch is shown at A, [Fig. 31], which represents the end of one of these cards, and a piece of one of the usual 8-row cards as here used is shown at B for contrast, the black dots in both cases representing holes.
These machines have not been adopted here, nor is it likely that they will be, although they are said to work well in France. They have been tried here, and the difficulty lay in setting the cards properly so as to act correctly on the needles, and keeping them so for any length of time. The least contraction or expansion of the paper, or any irregularity in the cutting, any bend in the points of the needles, or, in fact, anything but perfect exactness, interferes with the working: there is too great compactness in the machine, and in the ordinary wear and tear of work a little allowance is necessary for success. Considering that these are working, it would appear that the pitch and size of the holes in our cards are unnecessarily large, except where small machines answer and saving of space is no consideration; in that case the extra paper required for the cards might be more than compensated for by the strength of the machine, and the saving of trouble in attending to it.
Fig. 31
The method already mentioned of getting over the disadvantage of the single-acting jacquard is not likely to gain general favour, and is not required, as it is surpassed by the double-acting jacquard, or that in which there are two griffes, one rising when the other is falling, forming a counterpoise as well, making the shed more after the principle of ordinary tappet shedding. In a loom fitted with a single-acting jacquard, if there is much weight to be lifted, it will turn round the loom so that it will rest in no position but with the griffe down, and this is frequently of so much annoyance to the weaver as to necessitate a counterpoise being applied to balance it. Sometimes weights are used, and sometimes springs. With the double-acting lift nothing is required, and this was first used in Cross’s counterpoise harness (about 1816).
Fig. 32