[AS.] The natural covering of certain animals, the best known of which is the sheep. The sheep is a tame or domestic animal, but in certain countries, as Asia, North America, and in parts of Europe (Sardinia and Corsica), wild sheep still abound. The entire coat of wool growing on any one sheep is called its fleece. This fleece is usually cut off or shorn once a year. The countries producing most wool are England, Australia, Cape Colony, Saxony, Spain, United States, and Mexico. Wool is remarkable for its softness, and the wavy nature of the separate fibres. When the fibres are drawn through the fingers in one direction, they feel smooth; but in the opposite direction they are rough, and seem to catch. The wool, being cut and carefully prepared, is spun into yarn by a machine which twists the fibres together, so as to form them into a long thread; the waviness of the fibres and the projecting scales help them to hold firmly together. The yarn is then woven into cloth. Any piece of woolen stuff consists of two sets of threads-one set called the warp, running the long way of the piece ; and another set called the weft, running across, and interlacing with the warp. Lastly, the woolen cloth, as we may now call it, is dyed and pressed ; the nap is raised by a process called teaseling, and the material is then ready to be made into clothes. When wool is spread out in a thin layer, well moistened, and then beaten smartly with a rod, the fibres become matted together, and form a material called felt, of which hats, carpets, etc., are made. Wool is a bad conductor of heat, and so prevents its escape from the body. At the same time wool is a good absorber of moisture, soaking up the perspiration as soon as it comes out of the skin. Owing to the roughness of the fibres, woolen materials gently chafe or rub the skin, and so promote its healthy action.