well known, was to rise and take up the slack in the yarn caused by the "backing-off" or unwinding of the spiral of yarn upon the uncovered portion of the spindle, as previously referred to, and to retain the yarn in such a state of tension as to prevent it from running into snarls until the winding process had taken it up. During the progress of the latter the top faller would gradually rise, and the counter faller descend, until the winding was completed, when each would have regained their original position, there to rest until another draw or outward traverse of the carriage, forming another length of threads, had been completed. The top faller was actuated by means of compound levers, acted upon by rotary cams, which brought it down upon the threads, after which its movements were governed by a lever and friction roller, which traversed an inclined plane called “the shaper." This acted upon the faller, through the lever, in a different manner at every stretch, by which the successive layers were built up in such a manner as to form a well-shaped and firm cop, in many respects superior to the best that could be produced by hand.

The variable revolution of the spindles during winding was effected by a small drum placed at the end of the carriage near the headstock, to which the ends of two cords were attached, and coiled round it in opposite directions so that when one was being wound on the other was uncoiling. One cord was extended to the back of the headstock, and to its extremity a weight was suspended to act as a counterpoise, drawing the cord off the drum as the carriage drew away from the rollers, during which time the other cord was being wound up. This drum was also connected with some toothed wheels which were brought into gear with that part of the mechanism that operated the spindles during the time the yarn was being backed-off preparatory to winding on the spindle. The cord which caused the winding-on drum to revolve during the running in of the carriage had one end attached to the radial arm of a

quadrant which described an arc whilst the winding-on drum was receding from the point of attachment in a straight line. As the carriage receded the cord was uncoiled, causing the drum to revolve and thence the spindles. The amount of rotation of the spindles was regulated by the length of rope to be uncoiled. Assuming that all the parts were arranged for the commencement of work, and the spindles bare, the maximum number of revolutions would be required to wind on the length of a stretch or draw, but for winding the next a diminished number of revolutions would be required, owing to the winding surface having been increased by the previous layer. This was repeated with each succeeding layer until the bottom or base cone of the cop was completed. After this the movement was uniform until the completion of the cop or set. An accurate differential motion analogous to, but in its details radically different from that already described in connection with the roving frame, was therefore required and found in this arrangement. In this case the decrease of motion in the spindles was obtained by lessening the length of cord to be uncoiled from the winding-on drum. This was effected by making the point of the radial arm change its position with the addition to the cop of every stretch, so as to effect the required diminution in the length of the rope.

The first self-acting mule was one of the greatest triumphs of mechanical genius that has ever been achieved, and as a display of the power of the inventive faculty in man's nature surpassed anything accomplished up to that time. This statement hardly requires even that limited qualification, as though great advances have since been made in many branches of mechanical industry, nothing yet surpasses the spinning mule in the number and variability of its actions, the admirable concert of its parts, or the excellent results achieved by it.

The new machine was a perfect spinner; that is, it accomplished every part of the process without manual

help. Hargreaves' jenny and Crompton's mule required the aid of the operative to perform several processes. The inventor of the new mule dispensed with all necessity for this help, and transformed the operative spinner into a superintendent merely. Its chief features of difference from Crompton's mule, as improved up to that time, were :—1st, in the mechanism by which the faller and counterfaller were respectively depressed and elevated in backing-off and winding; 2nd, the regulation of the movements of these wires so as to make a well-formed cop; 3rd, the arrest of the twisting revolution of the spindles, reversing them for backing-off, the stoppage of this movement also, and a second reversal of the direction of the revolution of the spindles, with a slow and differential movement for winding up the yarn; and 4th, when all these were successively completed, the means by which they were automatically started anew.

The amount of inventiveness embodied in the new mule considerably exceeded that shown in the jenny or Crompton's machine, great as this was in each instance. Arkwright, as we have seen, was only to a limited extent a true inventor, being more distinguished for his ability to utilize the inventive faculty and labours of others, so that he can hardly be brought into the comparison. It must, however, be said in favour of Hargreaves and Crompton, that Roberts had facilities placed within his reach by the progress of mechanical science, and the improvement of machine construction, many advantages from which they were debarred. His genius was therefore comparatively unfettered, and hence achieved superior results. The value of his invention, however, can hardly be regarded as so great to the world as that of his predecessors, though the inventive skill manifested in it was superior. Hargreaves showed mankind how to do something essentially new and unthought-of before; Crompton wonderfully improved upon Hargreaves' plan, both in the manner of its action and the extent of its results; Roberts made a great step forward on the labours of both.

CHAPTER IX.

THE MODERN MULE.

Present comparative perfection of the mule.-The head-stock, with illustrations. Means of actuating the drawing rollers, spindles, and carriage. Stopping the carriage and the revolution of the spindles.-Backing off; movement of the faller.-Drawing in of the carriage.-Winding mechanism.-Harmonious operation of the parts in action. More detailed description; development of the various parts.-The faller wire motion, and its operation.-Building the cop.-The counter faller wire. -The backing-off mechanism.-The winding quadrant and its function. -Recent removal of several imperfections.--Copping apparatus controlling the backing-off movement.—The loose incline.—Improvement in the backing-off chain tightening motion; causes of its requirement.— Imperfection of the winding apparatus as left by Roberts.-Successive improvements.—Messrs. Platt Bros. and Co.'s automatic nosing motion. -Improvement in the click wheel. The stretching process in early mules; succeeded by the "gain."-The former plan retained for "medium fine" and "fine" mules.-"The jacking motion," and its adjuncts, the jacking delivery and the winding delivery motions of the rollers.Retention of the hand mule for the finest yarns.-Its improvement.Self-acting mule for finest yarns.-Backing-off and winding. The quadrant and its improvement.-Automatic regulation of the fallers; the lifting motion; locking and unlocking of the faller; winding; and backing off. Speed of the parts; changes; replacement.

HE brief review just given of the development of our principal spinning machine brings us to the period in which it is found with the essential principles and general structure and form it has since retained. All subsequent improvements, though considerable, have been in details. These have been perfected almost to the highest degree possible, and it would seem that little remains for succeeding inventors to accomplish in its further improvement, and this idea appears to be confirmed by the fact that of late years attention has been greatly diverted to the improvement of the flyer frame, in both its old form, and as

modified in the ring spinning frame. As, however, the mule is, and must long remain the most important spinning frame of the series, it will be well to examine it in detail before proceeding to the consideration of the claims of its rivals.

The following illustrations and description are reproduced from the article on "Cotton Manufactures," by the present writer, in Messrs. Spons' "Encyclopædia of Manufactures and Raw Materials," referred to previously:

Fig. 61 represents a side elevation of the mule headstock, with the transverse section of the carriage, shown as running in, and in the act of winding. The drawing-rollers and roller-beam are also seen in section. Fig. 62 is a front view. In Fig. 63 is seen a corresponding plan of the mule, showing the head-stock in the middle, and having spindles working on each side.

The driving power is communicated to the machine through the horizontal first-motion shaft, on which are the fast and loose strap pulleys A B.

When the carriage м has run in to the roller-beam, or drawing-rollers, the front of which series is seen at c3, the driving strap is on the fast-pulley A, though a portion extends to the loose-pulley B. Motion is communicated to the drawing-rollers by the small change bevel-wheel C, driving the large bevel-wheel c', running loose on the horizontal shaft c, and connected with the front line of drawing-rollers.

The spindles are also driven from the chief motor shaft by the double-grooved cord-pulley, or rim, a2, on the extremity of the shaft, carrying the bevel-wheel c. From this pulley, an endless cord a passes downwards, beneath the guide-pulley a1, thence to the oblique cordpulley a2, as seen in the carriage м, and to and around the tin roller a3, keyed on the horizontal shaft J, which carries the tin cylinders J1 used for driving the spindles. Thence it passes forward, and around the carrier-pulley a, fixed to the front of the frame, then along the floor to