Revolving Shuttles.—­The class of shuttles known as revolving or rotating, and which really consist of a combination of the disk shuttle and the earlier rotating hook of Wilson, have been under trial by several makers for many years.  If, for example, the oscillating shuttle we have just examined were to complete its circular movement, it would constitute a revolving shuttle, but would not be quite similar to those devices now known as such.  The most remarkable device of this kind yet introduced is to be found in Wheeler & Wilson’s machine known as No. 10 D, and invented by Mr. Dials last year.  It consists, in fact, of a detached hook, and its inventor declines to class it with shuttles at all, styling it a detached hook.  It consists of an exterior shell or skeleton of steel, capable of rotation in an annular raceway.  Its detachment from the axis forms a striking exception to the general construction of interlocking apparatus in this company’s machines.  Under the beak of this curious device is found an oblong recess, into which fits loosely a carrier or driver, rotating with a differential or variable motion.  The space between the carrier and the sides of the recess is sufficient to permit the free passage of the thread in encircling the shuttle, and the differential movement ingeniously releases the contact between the hook and carrier.  The skeleton of this device is only one-sided, and does not really carry its bobbin in the course of its revolution.  The bobbin is placed in a cup-like holder, which lies within the shuttle or hook body, and is retained in position by a latch hinged to the bed of the machine.  The cup and bobbin are prevented from partaking of the rotatory movement by a steel spur projecting from the cup, and fitting loosely into a notch in the latch.  Tension upon the under thread is obtained by passing it under a tension plate upon the bobbin cup.  Twisting of the thread is by these means entirely obviated.  In this apparatus, the disk-like appearance of the bobbin is partially lost in its considerable breadth, and there is thus a distinct departure from the lines of the ring shuttles before mentioned.  The diagrams exhibit the hook in several positions during its revolution, and the position of the threads corresponding thereto.

[Illustration:  FIG. 2]

Fixed Rotating Hooks.—­Wilson’s rotating hook for lock stitch machines, and Gribbs’ hook for single thread machines, are both well known.  In the year 1872, the Wheeler & Wilson company introduced a new hook, forming an improvement upon Wilson’s original device (Fig. 3).  Its chief peculiarity consists in the extension of the termination of the periphery, forming a long tail piece, quite overlapping the point, and serving as a guard, both to keep off the bobbin thread and to prevent collision between bobbin and needle.

[Illustration:  FIG. 3.]