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CHAPTER WIII.

ExTRACT's FROM THE SPINNING MASTER’s Assist ANT.

“To complete the wonder, this manufacture is the creation of the genius of a few humble mechanics; it has sprung up from insignificance to its present magnitude within little more than half a century; and it is still advancing with a rapidity of increase that defies all calculation of what it shall be in future ages.”—Baines.

Previous to the above work, published in Glasgow, 1832, nothing ever appeared in Europe on the art of cotton spinning, fitted to assist the master, manager, or artisan, in acquiring a correct and systematic knowledge of the real principles of the business. So that the manager of a cotton spinning factory could only acquire a proper knowledge of his business by long experience and application in the practical department of the manufacture, and it depended upon the situation in which he was placed, and the advantages he enjoyed, if he ever obtained that correct knowledge of all its details which is essentially necessary to render him fully qualified for managing a large establishment with satisfaction or profit to the proprietors. It is only when theory and practice are combined, that efficiency can be attained in effecting improvements. In all factories where there is a variety of machinery employed in the manufacturing of any particular kind of goods, it has always been found that the manner in which the machinery is placed, together with the arrangement of the different departments has a very prominent influence in either retarding or accelerating the progress of the work. But in no place is this influence more sensibly observed than in a cotton spinning factory. It is obvious, however, that the manner in which the machinery is placed, and the arrangement of all its different departments, will entirely depend upon the plan of the house, or the form in which it is built; hence the propriety and advantage of having a mill built on such a plan, or form, as to admit of having all the machinery placed, and the various departments arranged, in the manner best adapted for facilitating the progress of the work as a whole. The situation of the ground, or space upon which the mill is to be erected, must always be taken into consideration in laying

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down the plan or fixing upon the particular form in which the house is to be built; and in some cases this plan must just be made to suit the situation or place in which it must stand. But when the situation and extent of the premises are such as to afford ample scope for the proprietors to build their mill on any plan or form which they may think proper; in these circumstances, the house may be built in a form that will admit of having the machinery and the various departments and offices of the establishment, arranged in such a manner as to afford the greatest facility for accelerating the progress of the work in all the different stages or departments. They ought to be so situated as to prevent all unnecessary going to and from any of the different departments of the work, by the workers employed about the establishment. All the different offices, such as ware-room, picking-room, mechanic's shop, &c. ought to be contained within the walls of the mill, if possible, because there is always a continued communication with these different offices. A good ground plan of a cotton-mill, is 145 feet long, and 37 feet wide within the walls; with a wing attached to one end, 64 feet by twenty. A house of these dimensions would cover a space of about 7461 square feet, besides the stair-case and water-closets. A house 37 feet wide affords ample space for machines of 300 spindles each. A wing attaches to the body of the building, the various departments of which should be occupied for all the different offices, or separate apartments necessarily required about a cotton spinning factory. The body of the mill is supposed to be 145 feet long and 37 feet wide within the walls; and supposing it to be six stories high, a house of these dimensions would be capable of containing 23,000 spindles, with all the necessary preparation for average numbers. If steam was needed it would require an engine of between 40 and 50 horses' power to drive a mill of this extent. Every spinning factory ought to have a little more power than is merely necessary to drive it, because the weight of the machinery will often vary with the weather, the quality of the oil used, &c.; consequently, when there is barely a sufficiency of power, the engine will frequently be so overburthened, as to render it incapable of driving the machinery at a regular speed, thus requiring more trouble and expense for fuel, &c. This is worthy of attention where steam is used. The breadth of the mill being 37 feet, affords ample room for arranging all the different machines in the carding department in the best order, both for promoting the progress of the work, and allowing the different workers that are employed in this department to attend to their employments, without being in the least incommoded for want of sufficient room.

The length of the mill being 145 feet, would afford sufficient space for the spinning machines. Two upright shafts would be quite sufficient for driving all the machinery contained in a mill of this length. The cotton and waste cellars should be a detached building to lessen the risk. As the raw material is prepared in the carding room for all the spinning departments, the cards ought to be placed as near the centre of the mill as possible. A factory of the dimensions recommended above, six stories, would require two preparation rooms; these might be placed on the same floor with the picking-rooms. As there is always a constant communication between these two departments, if they are placed at a distance from each other, a great deal of time must unavoidably be lost in passing to and from the one to the other; but by this arrangement very little time will be lost; for the laps can be carried direct from the spreading machines to the back of the breaker cards, and the tops, strips, or other waste returned in the same way. An easy method for conveying the rove from the carding to the spinning room, should be adopted to save time and labour. The staircase ought always to be placed on the outside of the mill, and the outer door always kept shut during working hours. As it is obvious that the particular arrangement of the different departments, and the order in which the machinery is placed will always have a prominent influence upon the productive capabilities of large establishments, the advantage of having them arranged in the best manner which practical wisdom and experience can suggest, is so apparent as to require no force of language to prove it. And if such arrangements depend upon the particular form or plan upon which the factory is built, then the importance of having the different departments arranged in the most approved manner, is so obvious as to need no further comment.

The Method of calculating the Speed of the different Shafts and JMachines. In calculating the speed of the various shafts, the first thing to be done is to find the revolutions per minute of the first or main shaft; and when this is known, the principle upon which to proceed in tracing out the speed per minute of all the other shafts throughout the whole establishment, is both simple and easy to be understood. Suppose the first moving power to be a water whael; find how many revolutions it makes per minute, then, how many teeth are in the spur or bevel wheel. Multiply this number by the revolutions of the wheel per minute, and divide the last product by the number of teeth in the pinion acting in the same, and the result will be the revolutions of the first shaft per minute. But if the first moving power should be an engine, the first thing to be done is to find the number of strokes the engine makes per minute; and if the engine crank be attached to the wheel, then every double stroke of the engine will make one revolution of this wheel, and it will be the first driving wheel. Multiply the number of teeth which it contains by its revolutions per minute, and divide the product by the number of teeth in the pinion which is fixed on the end of the first shaft, and the result thus obtained will be the revolutions per minute of the shaft. And when the speed of the first shaft is thus found, the process of tracing out the speed of all the others, will be comparatively easy. Suppose an engine of 50 horses' power, and making 40 single strokes per minute, equal to 20 revolutions of the first shaft; therefore this shaft revolves 20 times per minute. Upon the end of the first shaft there is a large driving wheel, containing 96 teeth, driving the second shafts. Upon one end of the second shafts are two pinions containing 48 teeth each, driven by the large wheel. Upon the other end are two wheels, containing 56 teeth each, driving the upright shafts, upon the foot of which are the pinions, containing 32 teeth; upon the top of the upright shafts are the wheels, containing 54 teeth each ; these wheels drive the cross shafts. The pinions upon the ends of the cross shafts (which receive the motion from the upright shafts) contain 42 teeth each. Required the revolutions per minute of each shaft. RULE.—Multiply the speed per minute of the first shaft, by the number of teeth in the first driving wheel, and divide the product by the number of teeth in the pinion, which is fixed upon one end of the second shaft, and the result will be the speed per minute of the second shaft. In like manner, the speed of the upright shaft may be obtained by multiplying the speed per minute of the second shaft, by the teeth in the driving wheel, which is fixed upon the other end of the second shaft, and dividing the product by the number of teeth in the pinion which is on the foot of the upright shaft. And to find the speed of the cross shafts, multiply the speed per minute of the upright shaft by the teeth in the wheel on the top of the upright shaft, and divide the product by the teeth in the pinion on the cross shaft; and so by the same process, the speed of any shaft may be traced out, however remote, or at whatever distance it may be situated from the first moving power.

EXAMPLES. Speed per minute of the first shaft, 20 revolutions. Number of teeth on the first driving wheel, 96. Number of teeth in the pinion 48)1920(40 speed per minute of 192 second shaft. Speed of second shaft per minute, 40 revolutions. Number of teeth in the wheel, 56

Number of teeth on the pinion 32)2240(70 speed of upright shaft. Speed of upright shafts per minute, 70 Teeth in the wheel on the top of upright shaft, 54 42)3780(90 speed of cross shaft.

To find the speed per minute of any given shaft.

Rule.—Begin at the first moving power, and trace out all the driving and all the driven wheels separately. Multiply all the driving wheels together, and their product by the speed per minute of the first shaft; then multiply all the driven wheels together, including the first driven wheel on the given shaft, (the speed of which we wish to ascertain;) divide the product of the drivers by the produce of the driven, and the result thus obtained will be the speed of the given shaft. Required the speed of cross shafts.

EXAMPLE. Driving wheels. Driven wheels or pinions. First wheel, 96 | Second pinion, 48 Third wheel, 56 || Fourth pinion, 32 Fifth wheel, 54 Sixth pinion, 42 96 56 576 480 5376 54 21504 26880 290304 Speed of shaft 20

64512)5806080(90 speed of the cross shafts.

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