COTTON SPINNING. 



289 



Cotton for directing the yarn in winding up and building, or 

 Spinning;. f orm ; n g the cop, is at H. The three pullies, for the 

 — > - — single speed, the double speed, and disengaging the mule, 

 are at I ; the large wheel for driving the cylinder or 

 drums, as the case may be, which turn the spindles, is at 

 K. The smooth roads of iron, or, as they are usually 

 termed, the race roads, upon which the carriage moves, 

 are at LL; and the shaft, which moves the rollers until 

 the delivery ceases, is at M. 

 Plate Fig. 6. is a perspective view of the mule, as it would 



CCXII. appear at the distance of 10 or 12 feet from the left 

 F '£* & hand front corner. The guide H, and the connecting 

 shaft M, are omitted, because they would conceal other 

 parts if introduced, and also because they are sufficient- 

 ly laid down in Fig. 6 ; there being nothing materially 

 different in their construction from the common mule, 

 excepting that the arms of the guide are longer, in order 

 that the directing wire may descend, without interrup- 

 tion, over all the diagonal rows of spindles. All the 

 other letters of reference denote the same part in Fig. 6. 

 that they do in Fig. 5. The upper, or leathered rollers, 

 are also omitted, there being notlring peculiar about 

 them. 



We come now to the most essential and interesting 

 part of this subject, namely, the Comparison of this ma- 

 chine with those at present in use, and the immense sa- 

 ving of sunk capital of which it may be rendered pro- 

 ductive. For the sake of perspicuity, we shall arrange 

 this estimate under the three distinct heads, pointed out 

 in the introductory part of this section. 



1st, The Expence of Building. 



Eipence of We have seen that, by placing the spindles only one 

 building. inch asunder, a mule of 216 spindles will require a space 

 of 1 8 feet, exclusive of what is occupied by the framing, 

 and the space allotted for the driving pullies, and large 

 twining or twisting wheel. If four feet be allowed for 

 these, and only five feet more for passages round the 

 machine, the breadth of the building (within the walls) 

 must be 27 feet at least. 



The breadth of this machine (containing an equal 

 number of spindles) will be only six feet within the fra- 

 ming, to which, if we add the same allowance for fra- 

 ming and passages, we shall have 15 feet; and as only 

 one passage is required in the middle, we have two sets 

 of mules, with a middle passage of three feet, exactly 

 in the same bounds as were required in the former case. 

 Here, then, we have the number of spindles doubled in 

 the same bounds ; or, in other words, the saving upon 

 the building amounts to 50 per cent, or one-half of the 

 whole. 



2dly, The Expence of Power and Mill Work. 



Eipence of The saving of power will be found to be in a still 



power and g rea ter ratio. 



null work. j n trie ^fr.,tf place, we have only one-third part of the 

 drawing rollers to move, and have, of course, only one- 

 third of the weight, and one-third of the friction to over- 

 come. We have, indeed, the same number of spindles; 

 but as the house will contain two rows, and will be only 

 one half of the length, the whole is brought more con- 

 tiguous to the power, and one half of the weight, fric- 

 tion, and expence of the mill shafts will be saved ; be- 

 sides which, the engine will only require at most half 

 the power, and consequently may be erected at less than 



VOL. VII. PART U 



half the expence, and wrought with less than half the 

 fuel. 



3dly, Expence of Machinery. 



The expence of the machinery may very fairly be es- Expence of 

 timated in the same way. Two thirds in length of the machinery, 

 cross- railing, carriage, rollers, &c. will be entirely saved ; 

 and from the short and compact shape of the mule, eve- 

 ry part may be reduced in materials two-thirds, with 

 greater strength than before ; for the stress being as the 

 length multiplied into the weight, and two-thirds of each 

 being saved, the product will be in the ratio of 1 to 9, 

 or nearly so, when compared with the former. For if 

 the length be expressed by a, and the weight by b, the 

 stress will be as a b ; and if two-thirds are taken from 



each, the result will be -X -or — • The weight and 



expence of the whole shafts may be reduced in a similar 

 ratio, without any diminution of strength. 



After having maturely weighed this plan during some 

 years, and submitted it to the inspection of several ex- 

 tensive practical spinners, no objection whatever to its 

 practicability has ever been stated ; although it would 

 have been very natural to expect that those, who have 

 already embarked their property in establishments on 

 the present plan, from which it could not be withdrawn, 

 under any contingency, without an immense and ruinous 

 loss, would be far from desirous to promote, or even 

 sanction a plan, the very object of which is to enable 

 others to compete with them at less than half the ex- 

 pence. 



One objection, however, does exist, which, although 

 it does not appear impossible, nor even very difficult to 

 surmount, it ought to be candidly and explicitly stated, 

 in order to guard the engineer, who may attempt to re- 

 duce this plan to practice at an early period, against what 

 will prove his chief obstacle. 



The diagonal form in which the spindles are placed, 

 necessarily brings the threads much nearer to each other 

 than by the common plan ; and as some threads break 

 at almost every draught, there is reason to apprehend, 

 that the contiguity of the threads may, in this case, prove 

 of some practical disadvantage. A fractured thread, es- 

 pecially after having received a considerable degree of 

 twisting, has always a tendency to deviate from the 

 straight line in which it was stretched, and to entangle 

 itself with the adjacent threads. The nigher that the 

 threads are brought to each other, this disadvantage 

 must be the more increased, and consequently there 

 certainly exists a danger, that, in this plan, one thread 

 may frequently be the cause of breaking many, unless 

 some means be resorted to, to keep them asunder. The 

 tendency of a thread to deviate from the line in which 

 it was stretched, it is presumable, must be in the ratio 

 of the square of its length ; for its utmost possible de- 

 viation would be 90° from its former position before the 

 fracture. Hence we find that in spinning, if a thread 

 gives way at an early period of the draught, when the 

 spindles have receded but little from the rollers, it sel- 

 dom if ever does the smallest injury to the contiguous 

 threads ; and we also find practically, that the greatest 

 mischief is produced in twisting the threads at the end 

 of a draught, when the yarn is at its greatest stretch, 

 and when both the delivering rollers and the carriage 

 have ceased to move. On this principle, the following 

 2 o 



