"Another important feature of this operation is the speed at which the parts are allowed to work. The speed of the spindles, at the termination of the outward run, is too quick to allow of the use of the positive gearing already described, as it is found impossible to engage the parts sufficiently quickly. This difficulty is further increased by the spindles being quickened to the spinning speed directly the carriage finishes its inward run; for it is impossible to rely upon the momentum of the spindles for continuing their rotation during the lifting of the faller, the results being too variable. To overcome this difficulty, an extra driving belt, called the taking-in belt, is used for driving the self-acting pulley. This belt has generally about half the speed of the main rim-shaft belt, both belts working on pulleys of the

same diameter on the rim-shaft. Fig. 82 is plan of the headstock carrying the main driving or rim-shaft, r. The quick driving-belt runs on the fast pulley, a, and the loose pulley, B, whilst C and D are the fast and loose pulleys for the slower belt. Both belts receive their motion from the counter shaft, s (Fig. 83).

"The cam shaft has three changes in this mule. When the carriage is making its outward run, the quick belt is on its fast pulley, A, and the slow belt on its loose pulley, D. At the proper time, the cam shaft makes its first change, the rollers are stopped, and, when the proper amount of twist has been put into the yarn, the twist motion disengages the catch, which holds the quick belt on the fast pulley, A, and allows a spring to shift it

upon the loose pulley, B. This allows the backing-off to take place in the usual way; after which the carriage is caused to make its inward run, and, just before the termination, causes the cam shaft to make a second change, and shift the slow taking-in belt upon its fast pulley, c, whereby the rim-wheel, w, is then driven at a comparatively slow rate. It is whilst this slower speed has the control of the mule that the lifting apparatus does

R

Fig. 83. Driving belts and pulleys.

its work. The slower belt, when first shifted to its fast pulley, acts as a kind of brake on the momentum of the rim-shaft, R, and can be relied upon to give the same retardation in every stretch. When the winding faller has lifted nearly clear of the yarn, a finger on it comes into contact with the cam-shaft escapement, and allows the cam shaft to make a third change, which shifts the slow belt back from its fast pulley, c, to its loose pulley, D, and then shifts the quick belt on to its fast pulley, a,

causing the spinning to go on at the proper speed. So rapidly is the whole operation performed that it is impossible to see the change in speed from the slow to the quick belt, though, of course, it is easy to see the movement of the belts from one pulley to the other. The slower the operation, the more perfectly is it done; but it is found to be well done with spindles running at 1,500 revolutions per minute.

66

'During the outward run of the carriage, the various parts are replaced in their proper positions for repeating these operations. An apparatus is also used by which the winding faller, during the time it is being lifted, is enabled to govern the counter faller in such a manner that the counter faller is free to take up the slack yarn, if any, made during the rise of the winding faller, and is depressed below the yarn as usual, before the spinning commences again. Double speed motions are still used for the finest counts; but as this element would render the previous explanations more complex, it has been purposely omitted."

The preceding description of the parts of this wonderful machine, and of the function of each part, is so clear and full, that the student carefully reading it cannot fail to easily comprehend it; and the firm from which it emanates stands so high in the trade that it may be accepted as of indisputable authority.

A few remarks on fine spinning on the self-acting mule will appropriately close this chapter. Until within about ten years ago the prevailing opinion appeared to be that, however perfectly the self-acting mule might do its work in low and medium numbers, it could never be adapted to the production of very fine counts. The purely mechanical and inflexible nature of its movements would prevent its yielding in the slightest degree when, as was often the case in fine spinning, conditions required that this should be done. In the self-acting mule experience had shown that the carriage terminated its inward run towards the roller beam at such varying rates of speed that sometimes the backstops would hardly be touched, whilst at other times they would be struck with such force as to cause great vibra

U

tion throughout both carriage and roller beam. This would break down every thread were high numbers being spun. With hand spinning, on the contrary, the spinner could conduct the carriage home so gently as to avoid the final concussion, whilst even if it did occur he could wait until all vibration ceased before re-commencing, by which breakages would be obviated. The self-acting mule, however, being mechanical, could take no cognizance of this varying requirement. Again, the management of the faller wires by a good hand spinner was such as to prevent the breakage of the threads, but against the mechanical action of the faller in the self-actor, the resistance that could be offered by the threads, though sufficient in low and medium counts, would be quite insignificant in the highest counts. Experience for a long time seemed to justify these conclusions. The nice balancing of parts necessary to secure this sensitiveness in the machine, and its accurate performance of the various changes required to be made, were held to be points unattainable in the requisite degree of perfection in the self-actor. In spite, however, of this general opinion, these difficulties have been overcome, and to-day self-acting mules are at work spinning yarns as high in number as 350s, and which, with the requisite improvement in the preparatory processes, there is no reason to think will not be capable of spinning the highest numbers required. An old-established and eminent firm of machinists in Bolton, Messrs. Threlfall and Co., who have long made a speciality of fine mules, have succeeded in overcoming all the obstacles encountered, and have machinery from their establishment at work both in Lancashire and on the Continent producing as good or better work in the highest numbers than can be obtained from the hand mule. Thus the old organ-mule, which has so long held its ground as the best for this purpose, is being superseded, and will probably soon have disappeared.

CHAPTER X.

THROSTLE AND RING SPINNING.

DOUBLING.

The throstle, an improved form of Arkwright's water frame.-Description.-Attempts to improve it. The Danforth throstle. -The Montgomery throstle.-Shaw and Cottam's improvement.-Doffing, an expensive process; Bernhardt's doffing arrangement; the throstle ceased to be constructed.—THE RING FRAME; its popularity.-Defects of the throstle, the origin of the ring frame.-The throstle in the United States; reasons for its prevalence there.-Invention of the Ring Frame. -Practical defects in it; its rejection in England.-Its improvement, and re-introduction.-Success as a doubling frame.-Slow acceptance as a spinning frame.-The Booth-Sawyer spindle; the Rabbeth spindle. -The ring spinning frame for warp yarn; description; process of spinning; the traveller; the ring; the lifting chain; the lift of the bobbin. -Description of the Rabbeth spindle.-Doffing; the mechanical doffer. -Inclined arrangement of the rollers.-Ballooning.-The anti-balloon ring. The traveller clearer.-Increasing popularity of the ring frame. -Its use for spinning weft in the United States; the weft frame in England and on the Continent.-Doubling.-Doubled yarns.-The throstle doubling frame; disadvantages.-Improved throstle doubling frame. Characteristics of throstle-doubled yarns.-The twiner.Yarns from the twiner.-The ring doubling frame; its popularity.Description.- The English and Scotch systems.

TH

HE throstle is the second of the mechanical spinning frames calling for notice. As, however, in its principal form it seems likely to be superseded at an early date, a brief description will suffice.

This frame is simply an improved form of the water frame of Arkwright, and a gradual development from it. Compared with the latter, the changes introduced were that all the rollers upon each side were connected and actuated by a train of wheels driven from its first motion shaft. The method of driving the spindles was also improved by the introduction of the horizontal cylinder, which, as already pointed out, was one of the first improvements made in Hargreaves' jenny. The spindles