Of Spinning, and the Spinning .Teimnt When the robings are finished, they are brought to the spinning jenny, to com plete the spinning. The spinning jenny is an engine on the same principle as the robing billy, and only differs from it in having smaller spindles, more in number, and closer together ; the cops of robings are placed in it, as those of slubbings are in the billy, and by a similar management and operation are drawn out into the re quired fineness, and receive the degree of twist which forms them into cotton yarn.
Reeling. The cotton yarn, when taken from the jenny, is reeled, to ascertain its degree of fineness, and then laid by with others of the same sort : the reel used is a small wheel reel, which denotes the completion of the hank, or given num ber of yards, by a spring that slaps against its frame at that instant : its ma. chinery is the simplest used, and not dif ferent materially from the wheel reels common in other manufactures.
The cotton yarn spun on jennies is al most solely used for weft, which from its superior softness it is peculiarly fitted for, which softness is indispensably requi site for some fabrics. As yet no way has been found of forming yarn by mill spin ning of the same quality in this respect, and therefore the mill-yarn is almost en tirely appropriated for warp. This ma terial difference originates in the carding, which in that for the jennies lays the fibre of the cotton across the roll, while the carding engine for the mill-spinning lays the fibre longitudinally, in the direction in which it is afterwards spun, as will be more plain from the following description of this operation.
Of Mill Spinning. The cotton for mill spinning is cleared and beaten in a simi lar manner to that for jenny spinning, but is not washed or stowed; after it is judged to be sufficiently clean, it is brought to the carding engine.
mill Carding Engine. The principles on which this engine is constructed, are the same as those on which the carding engine for jenny spinning is formed: the great point in which they differ is, in the manner in which the carded cotton is taken from them, which, in the mill en gine, is so as to form an entire flake, or continued sheet, of the breadth of the last cylinder; the cards on this cylinder are generally formed of long narrow stripes, about an inch and a half broad, and are put on round it spirally, by which means there are no joinings in the longitudinal direction of the cylinder, of any consider able length. The carded cotton is struck
tiff this cylinder in the same way as from the other engine ; hut instead of being passed under the roller with longitudinal projections, to form it into rolls, it is drawn forward through a conical guide of tin, by two narrow wooden rollers, about six inches in diameter, that deliver it into deep and narrow tin vessels, in the form of a long ribbancl, about two inches in breadth. The mill engine, instead of the small carding rollers above the main cy linder, used in the jenny carding engine, has commonly narrow flat spars of deal, with cards attached to them, fixed at a proper distance from the principal cylin der. Toothed wheels and pinions are more used in the mill carding engine than bands ; but that this is any improvement is doubtful, as in other parts of the ma chinery of mills, bands have been substi tuted for wheel work to advantage, and probably will be more so than they are now, as they work without causing that shaking motion which toothed wheels oc casion in general, and which is both inju rious to the evenness of the yarn, and the duration of the machinery. For tooth ed wheels, when in quick motion, act by a succession of percussions on each other, unless constructed with an accuracy as to the form of the teeth, that is very diffi cult to give to very small wheels, or un less the teeth are so numerous that se veral may come in contact at once, which in small wheels would cause them to be of too reduced a size, and too weak for mill work.
From the carding engine the long stripes of carded cotton are brought to engines consisting merely of two pair of small rollers, one pair of which moves faster than the other, and each pair of which are caused to press against each other with some force, either by weights or springs. Here two, three, or more of the stripes of carded cotton are drawn out together into another stripe, smaller than the first stripes, and this operation is re peated till the stripes attain that evenness which is so essential to the formation of good twist.