the previously explained machines the cotton is deliv ered in the form of a very clean downy fleece, known as a "lap," having its constituent fibres thoroughly disentangled, yet not parallel. As the parallel condition is necessary before forming the roving from which the yarn is to be wrought, the lap must be subjected to the process known as " carding." As a regular and perfect roving is one of the first requisites for producing a perfect cloth, the carding is an important operation, as is evidenced by the constant efforts made by builders to produce carding machines of increased capacity and higher quality of result. The carder of to-day has many advantages not possessed by his predecessors of the last generation, his card-clothing and auxiliary machines being so much advanced and so superior that he cannot fail to obtain better results from the same quality of cotton. The object of the carding-engine is further to separate the bunches of fibres composing the lap by means of the very fine wires of the card-clothing, and then to re-form the fibres into a roll (the roving) in which the fibres are uniformly parallel.
Carding is one of the most important processes required in manufactur ing raw cotton-fibre into thread. That the work may be well done two conditions are requisite: first, in order to allow a " true" setting and to prevent unequal pressure of the working parts on the bearings and frame work, the carding-engine should be placed on a solid level floor where there will be no vibration: the ground-floor of the furnishes the most suitable location; and secondly, for the different parts of the carding-engine there should be selected proper card-clothing, upon which good carding mainly depends. The principle of the card-clothing will be understood from the following explanation.
Card-clothing consists of strips of leather in which are inserted fine wires, called " needles" or " teeth " (dents), having their projecting ends slightly bent in one direction. The teeth, which vary in size according to the quality of cotton to be worked, must be equally distributed and equally inclined over the surface of the leather. The card-clothing is fastened to flat or cylindrical surfaces of wood or metal, and the cotton is passed between two or more such clothed surfaces. It will he readily seen that the card-clothing is a very important factor in carding cotton, as it performs the peculiar function of separating the fibres and again com bining them.
Figure 6 (151. 36) shows a section of card-clothing for a " " roller. As this is the card-clothing with which the cotton first comes in contact, it must be strong, so as to remain uninjured by any impurities adhering to the cotton. Figure 7 illustrates the card-clothing used for
covering the main cylinder of a carding-engine when working a good staple cotton; Figure 8 (fiL 36) is the card-clothing required for the "dirt roller." The latter clothing is not so close set as the former, the purpose being to receive in its interstices the seed, leaves, and other impurities in the cotton, taken from the surface of the clo.$e-set card-clothing which covers the main cylinder. Card-clothing is designated by numerals, which indicate the number of wires to the square inch. The wires are either flat tened or round, coarse or fine, according to their required purpose.
Figures 4 and 5 represent two pairs of card-clothing bands of dif ferent modes of action. In Figure 4 the needles are set opposite one another in the direction of their points. Supposing the lower card-cloth ing covered (in any manner) with cotton and the upper (1)) moved over it to the right, hence in the direction opposite that of the arrow, the dents or teeth of the upper card-clothing will remove a portion of the cotton from all places of the lower where it is in excess and deposit it on those places which are empty or not sufficiently filled, the result of this simple opera tion being the separation of the fibres and their uniform distribution between the two surfaces. Figure 5 shows two strips of card-clothing with dents bent in the same direction. If the upper card (a) be filled with cotton and drawn over the lower in the direction of the arrow, the entire material will be transferred to the lower.
Carding-mackinc.—Upon the latter two modes of application is based the action of the carding-machine, also termed "carding-engine." Around a large cylinder or drum covered with card-clothing and revolving at great speed are placed a number of small rollers, called "workers" and "strippers," or a number of stationary top-cards, or both combined, so arranged that the cotton introduced by a feeding-apparatus is separated into filaments and wrought into a fiat, narrow strip or ribbon, termed a "sliver." This latter is then further drawn out, and thus reduced to a yet thinner and more attenuated state. The carding-engine shown in Figure 3 contains workers and clearers as well as top-cards and an auto matic cleaning-apparatus for the latter, thus representing this kind of machine in its most advanced form. Figure 2 shows a revolving flat carding-engine.