Before anything else can be done it is now necessary to remove the leaf particles, and to separate the individual fibres from their matted position. Both these functions are performed by the machine known as the Card, the principle of which is that of two surfaces armed with fine wire teeth revolving not quite tangent to each other. Originally carding was performed by hand, but the Wellman carding machine was one of the earliest textile inventions. This was considerably improved by the revolving flat card in 1857, the operation of which is somewhat as follows. [Illustration: PRINCIPLE OF THE FLAT CARD] [Sidenote: _Its Operation_] The lap from the finisher picker is fed over a plate on to a revolving cylinder bearing wire teeth, which combs it over a set of knives, thereby removing coarse dirt, and passes it on to a large cylinder armed with millions of fine wire teeth. The latter carries the cotton past a slowly revolving endless chain of flats which remove the neps and fine dirt. The clean, separated fibres are then picked off the cylinder by a smaller rapidly revolving roller called the doffer, which carries them in a filmy sheet to be in turn removed by the doffing comb. The latter, working so rapidly that the eye fails to see it, lifts the sheet of fibres clear so that it may be passed through a funnel and condensed into a single untwisted rope a little under an inch in diameter. This rope is called a sliver, and is automatically coiled into a can like an umbrella-stand. [Sidenote: _Counts of Yarn_] [Sidenote: _Two Processes_] [Illustration: _Feed End of Card. Lap Entering_] [Illustration: _Delivery of Sliver_] We have now for the first time reduced the raw material to a continuous strand, comparatively free from impurities. Up to this point, no matter what kind of yarn is to be spun, the operations are practically identical, but from here on the processes vary according to the product desired. A hank of yarn is 840 yards (not to be confused with the worsted hank of 560 yards) and the number of hanks it takes to make a pound is the basis upon which yarn is classified. Thus a coarse yarn which weighs only twenty hanks to the pound, would be called 20s, while 80s would be a very fine yarn. Various fabrics require different grades of yarn, just as different finenesses of yarn must be spun from varying grades of cotton. The processes preparatory to spinning vary, not only with the counts to be spun, but with the use to which the yarn is to be put. Ordinary coarse and medium yarns for weaving usually follow one process, while fine counts for weaving, or knitting yarn, or coarse yarn made from long-staple cotton such as that used for tire-duck, go through a different preparation. The former are simply drawn and reduced, while the latter are in addition combed. [Illustration: _Drawing_] [Sidenote: _First Process_] [Sidenote: _Drawing_]