Of the twenty or more varieties of cotton but two are given much attention in the United States. These are the famous sea island cotton and the common, woolly-seed kind. The sea island cotton grows on the islands off the coast of South Carolina, in Florida, and on the coast of Texas. The peculiar salt air and humidity of these coasts seem necessary to its perfection, for when it is planted in the interior it quickly loses its best qualities and becomes similar to the common variety. Its fibers are long and silky, and used for the finest laces, spool cotton, fine muslins, and such goods, but there is so little of it as compared with the woolly seed cotton that it is but an insignificant part of our great crop. Cotton is the only fibre that is naturally produced ready to be worked directly into cloth without special chemical or mechanical treatment. It is the great article of comfortable and cheap covering for man's person. When gathered and baled it is in a knotted and lumpy state, from which it is rather difficult to extricate the fibers and arrange them for spinning. As we follow the cotton through the mill we come to these machines in the following order: It goes to the opener first, where it is beaten and spread out so that a strong draft of air drives out much of its impurities; it then goes to the scutcher after being formed into laps; the lap machine makes it into flat folds; the carding engine not only cards it but straightens the fiber and gives it another cleaning; in the drawing frame it is arranged in loose ropes with the fibers parallel; then the slubbing frame gives it a slight twist; the intermediate and finishing frames twist it still farther, especially when preparing it for the higher numbers; the throstle frame prepares coarse warps; and on the mules, either self-acting or hand, the coarse or fine yarns are spun. In some systems several operations are performed by the same machine. Weaving follows. It consists in passing threads over and under each other as a stocking is darned, the main difference being that in darning the needle passes up and down to get over or under the threads it meets, while in weaving the threads met by the moving thread move out of the way so the shuttle may pass straight through the whole width of the cloth. As the shuttle comes back the threads are reversed so that the ones that were up before are now down and those that were down are now up. The machine that holds many threads for this work is the loom.