COTTON SPINNING. The spinning of cotton into the form of yarn, or thread, re of these consists in mixing the contents of difflrent bags together, to equalise the quality. Thh is done by spreading out the contents of each bag in a horizontal layer of uniform thicAness, the contents of the several bags forming separate layers and resting one upon the other, so that the number of layers cor responds to the number of bags. The cotton of which this heap is composed is then torn down by a rake from top to bottom. It is evident that in its progress a portion of each horizontal layer will be brought away, and that thus, if the work be skilfully done, the contents of the different bags must be collected together in a mass of uniform quality. The mode of conducting the mixing depends on the quality of yarn required.
The scutching-machine is used to open the locks of cotton and separate its fibres, while at the same time it separates from it any sand or seeds which it may contain. This machine consists of feeding rollers made of wood, and placed at a short distance from each other, through which the cotton is made to pass slowly. After passing through the rollers the cotton is struck by a set of beaters made to revolve 1000 or more times in a minute. The cotton is passed through two sets of rollers, and subjected to two sets of beaters.
Up to this stage the fibres of the cotton cross each other in every direction. The use of the carding-engine is to disentangle them, to draw them out, and to lay them parallel to each other. The card is a species of brush made of short wires passed through a sheet of leather and pointing all in one direction. In the early period of cotton-spinning in this country, these cards were nailed on small pieces of board with handles, and two of them were used together, one held in each hand. Hargreaves invented an improved arrange ment of cards in 1780 ; but this gave way to the cylinder machine, now universally em ployed. This consists of a horizontal cylinder covered with narrow fillet cards, studded with wires. Over the cylinder is a concave frame, the interior surface of which is lined with cards, and the form of which corresponds to that of the cylinder. When the cylinder is made to revolve, the cards on it and on the frame work against each other, by which means the fibres of cotton are disentangled and properly arranged, as already mentioned. The cotton is spread out into a sheet of given length and breadth, and placed so that the teeth of the earding-engine can catch it and draw it in. A sort of comb draws the fibres of cotton off the teeth when the carding is effected ; and the cotton passes through two rollers into a tin can, where it assumes a light fleecy form called a sliver.
The next operation, that of drawing, has for its object the arranging of the fibres of cotton longitudinally, in a uniform and pa rallel direction, and to remedy all existing inequalities in the thickness of the sliver. The drawing-frame acts upon the same prin ciple as Arkwright's spinning-frame, two sets of rollers being employed moving with unequal velocities. The cotton is drawn several times, to attain the utmost regularity.
Roving, the next step in the process, is a continuation of the drawing, with this only difference, that the cord, now called a rove or slub, being so much reduced in thickness that it will not otherwise hold together, a slight twist is given to it by passing it into a conical can, which, while receiving it, is made to re volve with great velocity. The rove, thus
slightly twisted, is wound upon bobbins by children, and is then ready for the spinning frame. The fly frame and the tubeframe are two machines employed in this process.
The principle of Arkwright's spinning-frame has been already explained. [Aurrwuroar.] The throstle-franze is the same in principle as Arkwright's invention, but the movement of the parts is simplified. A throstle-frame now contains from 70 to 150 spindles on each side ; and one young woman can manage the double set, from 140 to 300 spindles. The Mule Jenny, invented by Samuel Crompton, com bines the essential principle of Arkwright's frame with the property of stretching pos sessed by Hargreave's Jenny. By means of the mule-jenny, the roving is first drawn and then stretched. The effect of this improve ment is to make the yarn finer, and of a more uniform tenuity. The spindles in this ma chine are regularly arranged on a carriage, which, when put in motion, recedes from the rollers with a velocity somewhat greater than that at which the reduced rovings are delivered from them; during this time the yarn is re ceiving its twist by the rapid revolving of the spindles, and when the rollers are made to cease giving out the rovings, the mule-jenny still continues to recede, but with a slower motion, and its spindles to revolve, and thus the stretching is effected. When the drawing, stretching, and twisting of the thread are thus accomplished, the mule disengages itself from the parts of the machine by which it has been driven, and then the attendant spinner returns the carriage to the rollers, again to perform its task. While returning to the roller, the thread which has been spun is wound or built on the spindle in a conical form, and is called a cop. The mule-jenny has become a self acting machine; by some beautiful inventions of Messrs. Sharp and Roberts, at Manchester. Some of the modern double self-acting mules contain 2200 spindles, all managed by one man.
The spun yarn is reeled into hanks con taining 840 yards. Yarn of low numbers, or below 40 hanks to the lb., is generally spun by the throstle ; but high numbers, or fine yarn, is more frequently spun by the mule. At Houldsworth's Mill, at Manchester, yarn was spun a few years ago to the astonishing degree of fineness of No. 460; that is, 460 X by 840, or 386,400 yards, or nearly 220 miles in length, from 1 lb. of cotton. This yarn was worth five times its weight in silver, and was spun for a muslin dress for her Majesty. But even this triumph of skill is about to be exceeded. A Manchester manu facturer is spinning a pound of cotton for the Great Exhibition of 1851, in length 238 miles and 1120 yards, being the finest ever yet produced. Those most conversant with the details of cotton-spinning can best appre ciate the value of the machinery and the talent displayed in so wonderful a production. The cotton was, we believe, from Egypt, and is considered the finest specimen that was ever imported into this country.