COTTON MANUFACTURE embraces ' so many operations, each of which is per formed in various ways, and by mechan ism variously termed, that it requires a volume of ordinary size to give a full de setiption of it. It is impossible, in the limits here assigned, to give more than a faint outline of the most connnon pro cesses.
The first process is that of separating and spreading it out in a light unitbrol mass, and is termed batting and scotch ing, or willeying and spreading, according to the description of machinery employed for the purpose. This machinery consists, mainly, of revolving beaters which beat the cotton against gratings or screens, through which the dirt, sand and short broken fibres are blown by fans.
The next process is that of carding, which serves to equalize the substance of the cotton, and dispose the fibres in a parallel direction. The carding engine consists of a revolving cylinder covered with cards, which is nearly surrounded by a fixed concave framing also lined with cards, with which the cylinder comes in contact. From the cylinder, called the breaker, the cotton is taken out by the motion of a transverse comb, called the tinging plate, and passes through a second carding in the finishing cylinder.
The cotton leaves the carding-engine in the state of a delicate, flat, narrow strip or ribbon, called a sliver ; and these sli vers have now to be converted into draw ings, by being elongated, narrowed, and thinned to a still more delicate condition. This process is one to which Arkwright paid particular attention, as having an important influence on the quality of spun cotton. In the first place the sli vers are collected in tall cans, generally either four or six in number, on one side of the drawing frame, and are from thence carried upwards to two pairs of rollers, the two rollers of each pair re volving in contact. Here all the slivers or cardings are collected into one group, and are drawn between the rollers by the ro tation of the latter. Now if these rollers are revolved equally fast, the cotton would leave them with the same united thickness as when it entered ; but the last pair revolves quicker than the first, so as to draw out the cotton in a more attenuated ribbon ; because the more slowly-revolving rollers do not supply the material fast enough for the main tenance of the original thickness. This is perhaps the most important principle in the whole range of the cotton manu facture ; for it is exhibited alike in the present process and in the next two which follow. All the four or six slivers
are connected into one before being caught between the rollers ; and after leaving the rollers, the united "drawing" passes through a kind of trumpet-shaped funnel, and is thence conducted into a tall can, round the interior of which it recoils itself. One consequence of the drawing process, if properly conducted, is, that the drawing is perfectly equal in thickness in every part, and formed of parallel fibres; and in order to insure this, the drawing is repeated more than once, each narrow ribbon being bled" with others before each successive drawing.
The preliminary spinning process is called roving. At first the torsion is slight in proportion to tho extension, since the solidity of the still coarse sliver' needs that cohesive aid only in a small degree, and looseness of texture must be I maintained to facilitate to the utmost the further elongation.
Fig. 33, is a section of the can roving frame, the ingenious invention of Ark wright, which, till within these 14 years, was the principal machine for communi cating the ineipient torsion to the spongy cord furnished by the drawing heads. It differs from that frame in nothing but the twisting mechanism • and consists of two pairs of drawing rollers, a and b, be tween which the sliver is extended in the usual way ; c are brushes for cleaning the rollers ; and d is the weight which presses the upper set upon the lower. The wiping covers (not shown here) rest upon a b. The surthce speed of the pos terior or second pair of rollers is 3, 4, or 5 times greater than that of the front or receiving pair, according to the desired degree of attenuation. Two drawn sli F vers were generally united into one by this machine, as is shown in the figure, where they are seen coming from the two cans a 6, to be brought together by the pressure rollers, before they reach the drawing rollers a b. The sliver, as it es capes from these rollers, is conducted into the revolving conical lantern g, through the funnel f at its top. This lantern-can receives its motion by means of a cord passing over a pulley k, placed a little way above the step on which it turns. The motion is steadied by the collet of the funnel!, being embraced by a brass busk. Such a machine generally con tained four drawing heads, each mounted with two lanterns; in whose side there was a door for taking out the conical coil of roving.