=First, the wool is sorted.= Wool sometimes travels a long distance before it is delivered to the manufacturer. Perhaps the wool in your skirt was grown in England or in Australia, and was shipped in great sacks to New York, and then to the manufacturer. As it is sheared from the sheep, it is dirty and full of burrs, grease, and perspiration. This grease helps to preserve the wool until the manufacturer is ready to use it; and, although he buys the wool by weight and pays for dirt and grease, he prefers to do so because of the preserving qualities of the grease. Even ⅔ of the weight may be dirt and grease. The first thing the manufacturer does is to sort the wool to put the good grades together, and to separate them from the poor ones. You remember the fleece is the whole coat of the sheep. Some parts of this coat are better wool than others; especially the part from the head and upper part of the back and sides. About seven different grades are separated for different purposes. [Illustration: _Courtesy of M. J. Whittall._ FIG. 121.--Wool washing or scouring.] =The second process is washing or scouring.= Wool cannot be carded and spun until the dirt and grease are removed; so the next thing the manufacturer does is to remove the grease, or "yolk" as it is called, by washing. This must be done very carefully so as not to break or injure the wool. Perhaps you can bring some dirty wool from your farm to school and wash it. Soft soap is the most harmless. Use a soft water at a low temperature (120° F.). Can you tell why it must be low? The washing is done in a series of tanks. You can see them in the picture (Fig. 121). The wet wool is swished back and forth by means of wooden forks which carry the wool forward and beat it out. There are rollers for passing the wool from one tank to another. Then the wool must be dried. This is done in a kind of wringing machine called a "hydro extractor." Then it is beaten into a fluffy mass. Then a strange thing happens. Oil in wool is necessary in order to help in the spinning and to keep it soft and elastic, so the manufacturer must return some oil to the wool, after having washed it all out. Olive oil is used. If there is any dirt or any burrs left in the wool, they must be removed. A machine called a burr picker is used to beat out the dirt.