994 COTTON-SPINNING 



exceeded tho most sanguine expectations, and which has been extensively adopted. 

 The advantages gained by Mr. Eoborts's improvements are tho saving of a spinner's 

 wages to each pair of mules, piecers only being required, as one overlooker is suf- 

 ficient to manage six or eight pairs of mules ; and the production of a greater quantity of 

 yarn, in the ratio from 15 to 20 per cent. Tho yarn possesses a more uniform degree 

 of twist, and is not liable to be strained during the spinning, or in winding-on, to 

 form the cop ; consequently fewer threads are broken in these processes, and tho yarn, 

 from having fewer piecings, is more regular. 



The cops are made firmer, of better shape, and with undeviating uniformity ; and, 

 from being more regularly and firmly wound, contain .from one-third to one-half more 

 yarn than cops of equal bulk wound by hand ; they are consequently less liable to 

 injury in packing or in carriage, and the expense of packages and freight (when 

 charged by measurement) is considerably reduced. From the cops being more regu- 

 larly and firmly wound, combined with their superior formation, the yarn intended 

 for warps less frequently breaks in winding or reeling, consequently there is a consi- 

 derable saving of waste in those processes. 



Several improvements have been made in the construction of self-acting mules since 

 the date of Eoberts's patent, but none of them have marked so decided a. step forward. 

 The more prominent of these may be briefly noticed. 



In 1834 Mr. James Smith obtained a patent for a method of dispensing with the 

 ' backing-off motion ' of Boberts. Instead of reversing the movement of the spindles, 

 in order to clear the spindle point and arrange the thread conveniently for the 

 wiuding-on process, ho elevated the counter-faller and thus, whilst the spindle was 

 stationary, ' stripped off" the spiral coil of thread from the spindle in an upward 

 direction. This method is still in use ; but as it subjects the thread to considerable 

 strain, it is generally used only for the coarser and stouter yarns. More recently 

 patents have been taken out for improvements in mules, by Mr. Potter, of Manchester. 

 Messrs. Higgins and "Whitworth of Salford, Mr. Montgomery of Johnstone, Messrs. 

 Craig and Sharp of Glasgow, and many others. 



Mr. Eoberts's self-acting mule, which was practically the first introduced, and with 

 several modifications in its construction, is still tho mule which is most extensively 

 used and approved in the cotton trade. Some of tho more prominent of these modi- 

 fications have been effected by Messrs. Parr, Curtis, and Madeley of Manchester. Of 

 these the f> Jowing summary gives the principal features, viz. the substitution of a 

 catch-box with an excentric box, in lieu of a cam shaft, to produce the required 

 changes ; an improved arrangement of the faller motion, which causes the fallers to 

 act more easily upon the yarn, and not producing a recoil in them when the ' backing- 

 off" takes place, thus preventing ' snarls ' and injury to the yarn ; in applying a spiral 

 spring for the purpose of bringing the backing-off cones into contact, by which the 

 operation of ' backing-off' can be performed with the greatest precision. The backing- 

 off movement is also made to stop itself, and to cause the change to be made which 

 affects the putting-up of the carriage, which it does in less time than if an independent 

 motion was employed. They have also an arrangement for driving the back, or 

 drawing-out, shaft by gearing in such a manner that in the event of an obstruction 

 coming in the way of the carriage going out, the motion ceases and prevents the mule 

 boing injured. 



By means of a friction motion, the object of which is to take the carriage in to the 

 rollers, the carriage will at once stop in the event of any obstruction presenting itself. 

 For the want of an arrangement of this nature, lives have been lost and limbs injured, 

 when careless boys have been cleaning the carriage whilst in motion, and have been 

 caught between it and the roller beam, and thus killed or injured. 



Another improvement consists in connecting the drawing-out shaft and the 

 quadrant pinion shaft by gearing, instead of by hands, thereby producing a more 

 perfect winding-on, as the quadrant is moved the same distance at each stretch of the 

 carriage. They have also made a different arrangement of the headstock or self- 

 acting portion of the mule causing its height to be much reduced, which makes it 

 more steady, offers less obstruction to the light, enables the spinner to see all the 

 spindles from any part of the mule, and allows a larger driving strap, or belt, to be 

 used, which in low rooms is of considerable importance. The result of these various 

 improvements is tho production of one of the most perfect spinning machines now in 

 the trade. 



For spinding very coarse numbers, say 6's, they have patented an arrangement, 

 by which the rotation of the spindles can be stopped, and the operation of backing- 

 off performed, during the going-out of the carriage, thus effecting a considerable saving 

 of time. 



The following is a description of one of these mules : 



Fig. 581 is a plan view \Jig. 582 a tranverse section ; and fig, 583 an end view, of so 

 much of a mule as is requisite for its illustration here. 



