This Machine is represented in [Plate 34], at [figs. 3 and 4]. It consists of a frame of wood or metal A B, on which are mounted the following objects:—1st, on the traverse B, a fixed tube, having for it’s base the horizontal plate a b, and rising perpendicularly to near c d; where it unites with a conical or trumpet-like vessel c d, f e; the left side of which is shewn in perspective, and the right side in a section only. To this fixture is adjusted the spherical portion g h, h, prepared to receive several cuts or slits 1 2 3 for the bobbin-slides hereafter-mentioned, to slide up and down in. This leads us to observe the upper fixture C, which is a cylinder, terminated downward by a spherical dome i k, k; also receiving the several cuts 4, 5, 6, into which the aforesaid bobbin-slides pass from the former slits 1, 2, 3, &c. Now it will be seen that the two spherical parts thus fixed, are separated from each other by the circular and horizontal slit l m, whose use is to permit the pipes shewn in the section at n o, to circulate all round the machine, while the bobbin-slides and bobbins k p are sometimes above and sometimes under the said slit l m.
Now, then, it becomes necessary to speak of the cause of this passage of the bobbin-slides from the under to the upper parts of the slits 1, 4, 2, 5, and vice versa. That cause is in the second dome q r, which covers, as far as it rises, the inner dome f i, k h; and it consists in a serpentine canal, of which a section is given to the left of q, and at s, in the section of the principal figure.
But to make this important piece of the Machine better known, I have drawn it apart, in [figure 4], on the supposition—that it is a portion of a cone instead of a sphere: I say a cone drawn with the radii t q, t r, according to the dotted line t r. The surface then of this cone, is supposed straightened in the lateral figure; and the aforesaid serpentine canal is shewn at a b c d e, having the rollers of the bobbin-slides placed in that canal, at the same points a b c, &c. Here also, certain dotted lines f g, h i, &c. shew the relative positions of the slits 1 4, 2 5, &c. of the principal figure, and also of the horizontal slit l m: whence it appears, that the revolution of the bent canal, a b c, &c. must some times drive the rollers towards g i, &c. and sometimes towards f h, &c. while the pipes n o pass undisturbedly round the Machine, in the horizontal slit l m of both figures.
The question now arises, how is the circular motion given to the outer dome q r of the principal figure? that dome is screwed to the cone r v w r, being itself of one piece with the hollow tube v w, on which the wheel x y is fixed. Now, this wheel x y, is driven by a vertical wheel z, of twice the diameter, for a reason we shall soon disclose.
It remains now, principally, to speak of the drawing-system of this Machine, shewn, in small, at c, and of a natural size in [fig. 5] of this [Plate]. That Machine has also it’s own tube c x′, working inside of the fixed tube a b, &c. and terminated, at bottom, by the wheel x′, which turns it by means of the second vertical wheel x′ z, fixed on the same axis as the wheel z before-mentioned, and of half it’s diameter.
Supposing then, for the moment, that the mechanism c derives from it’s circular motion, the property of drawing downward the threads from the pipe n o, and the bobbin p; (being one of the twelve pair distributed round the Machine) we shall now set the Machine at work, for the purpose of viewing it’s operation a little more narrowly. Looking at the two kinds of texture, indicated in the figure below the traverse B, we see that on the left composed (in weavers’ language) of a straight warp, crossed by an oblique weft; and this I believe, is the common texture of round, small ware, as usually woven: the slope of the weft being less and less as the number of shuttles diminishes, insomuch that with one shuttle that slope, might become almost invisible. But in the work made on this Machine, where, virtually, there are as many shuttles as threads in the chain, the slope would become very perceptible, too much so, perhaps, to give a desirable appearance to the work; although the rapidity of execution, from the multitude of crossings, would compensate for some imperfection of that kind. But, in fact, this Machine is intended to make a diagonal or diamond texture, as in the specimen to the right hand: and that is the object of the two pair of wheels x y, with z; and x′ with x′ z before mentioned. Their effect is this: when the large vertical wheel z, has turned the outer dome and the pins n o, once round the common centre, the smaller vertical wheel x′ z, has turned the drawing-system c, just one half as much round that centre, and thus sloped the threads coming from the fixed slits in which the bobbins move, as much, in one direction, as the whole turn given to the pins n o, has sloped the other half of the threads in the other direction, and the result has been the aforesaid diagonal texture.