SPINNING. ■449 SPINNING. greater length that their revolutions exceed those of the other pair, and as the first roving is passed though a second, third, and sometimes fourth ma- chine, the finished roving is 32 times longer than the sliver. As the roving issues through the last rollers of each machine it is received on spools or reels, calculated to hold a given quan- tity; and these are transferred to the sjihitung frames, which resemble the roving frames. Here the roving takes the place of the sliver, and, as it unwinds from the spool, is drawn through suc- cessive pairs of rollers, moving as before at differ- ent rates, each succeeding pair faster than the backward ones, so that the roving gets thinner and thinner, until the tenuity is carried as far as is fed to it in a hopper or by some kind of au- tomatic feed, and delivered in laps which are then placed on the intermediate lapper, either 3 or 4 laps being 'doubled' on the same and the cot- ton after being loosened and further cleaned is delivered in laps to be placed on the finisher lapper, 3 or 4 laps from the intermediate being again 'doubled' and delivered in a single lap ready for the card. The function of the lappers is to thoroughly loosen the lumps of cotton as taken froni the bale, to remove dirt and dust and as much leaf, trash, and motes as possible. There are usually three of these, the breaker, in- termediate, and "finisher lapper. Fig. 1 is a sec- tion of an intermediate or finisher lapper. The Squeeze-rolls/ Beater Feed Rolls / Dust-flue B^ Fia. 1. SECTION OF INTERMEDIATE? OR FINISHER LAPPEB. desirable. It is then carried on to a spindle which revolves with great rapidity, and, by means of a simple arrangement, is made both to twist the thread and wind it on the spindle ready for the weaver. It was found that the process of spinning by rollers produced too great a strain upon the thread in its progress to admit of its being drawn as fine as is wanted for many purposes, and this led to the invention of the mule jenny by Cromp- ton in 1779, which has a traveling frame upon which the spindles are set, and w'hich in its mod- ern form is described below. During the nineteenth century many important improvements were made in the details of the construction of spinning machinery, but the gen- eral principles are those worked out a hundred j'ears ago. The greatest improvements have been changes in the construction of spindles, allow- ing them to revolve more rapidly and freely. In the modern factory spinning is the final process in a series of operations necessary to convert the raw fibre into thread. Each of these pro- cesses has for its object the removal of smaller and smaller impurities and the production of a finer and stronger thread. These are: (1) open- ing and picking; (2) carding and combing; (3) drawing; (4) roving; (5) spinning. Other in- termediate operations may be introduced. The opener or breaker lapper is a similar ma- chine to the intermediate or finisher lappers, as shown in Fig. 1, and described below. In the breaker lapper the cotton as taken from the bale cotton enters these machines in a sheet made up from the laps, A, delivered onto the slowly mov- ing apron, from which it is taken by the feed- rolls and delivered to the rapidly revolving beater, which forces it against the grid-bars, loosening the dirt and motes which fall through the grids into the mote-box. The cotton is left in a light and feathery mass which is drawn be- tween the squee:c-rolls by the suction of the fan, ■which also draws the dust and fine dirt from the beaten mass and discharges them through the dust-flue. The sheet of cotton from the squeeze- rolls is taken by the calender-rolls, and com- pressed and finally rolled into the lap B. The lap is about one inch in thickness, 40 inches to 48 inches wide, and usually from 48 to 52 yards long. After the cotton has passed through the series of lappers the laps from the finisher lapper go to the card (Fig. 2). (See Carding.) The cot- ton in the lap A is delivered to the feed-roll of the card and is grasped by the teeth of the Ucker-in or takcr-in, from which it is taken in a thin sheet by the fine wire teeth of the card-clothing on the cylinder B, and carried upward to come in contact with the teeth on the clothing of the tcrp-flats, and the fibres are combed into a degree of parallelism — the cylinder revolving rapidly, while the flats, which are in a chain, move slowly forward so that new fiats are continually coming in contact with the cylinder — and much of the short and broken fibres is re- moved: the comb, C. removes tlic short fibres
