70 



These waves, or bends, are called the " crimp " of the wool. When the 

 waves are very close tog'ether, the crimp is said to be fine, so that fine 

 wool has fine crimp, and coarse wool has coarse crimp. 



But there is another difference between wool and hair. If you 

 get a sing-le fibre of wool, and take hold of the end that grew next to 

 the body of the sheep, and then draw the fibre between the finger and 

 thumb of the other hand, you will find that it slips through very 

 smoothly. But if you take hold of the other end of the fibre, and then 

 draw it between the finger and thumb as before, you will find that it 

 seems to catch, and does not slip between the fingers nearly so easily. 

 Whv is this ? It is because every wool fibre has hundreds of very, very 

 small scales on it, something like the scales on a fish, only so small 

 that they cannot be seen without looking at the wool with a microscope, 

 which makes the wool fibre appear many times larger than it really is. 

 These tiny scales all point towards the outer end of 

 the vool fibre, so that when you took hold of the outer 

 end ot the fibre and tried to draw it between the 

 fingers of the other hand, the points of these little 

 scales caught on your fingers and made it hard to pull. 

 The picture. Fig. 92, shows how these scales grow on 

 the wool fibre, but the fibre and scales are made to 

 appear very much larger than their natural size. Hair 

 also has scales upon it, but the points of the scales on 

 the hair are rounded, and they lie so close to the 

 hair that they do not catch hold of anything the}' rub 

 agrainst ; while the scales on the wool fibre have sharp 

 points and rough edges, so that they catch and cling 

 to everything they touch. This difference in the kind 

 of scales, is the most important difference between 

 wool and hair. 



Now, when the weather grows warm in the spring, 

 the sheep does not need its warm winter coat and so 

 the farmer clips it all off, or shears the sheep, as we 

 say. The wool is then sold, and is sent to the large 

 factories where it is made into all sorts of clothing, 

 blankets, yarn, and other goods. 



Before it is made into cloth, the wool is twisted, or 

 spun mto yarn. If the wool fibres had no crimp, they 

 would not stay tightly twisted together, and the yarn would be of very 

 poor quality. Then the yarn is woven into cloth by machines, and the 

 way the wool is handled in spinning and weaving causes the little scales, 

 which we have described, to catch into one another, and the wool fibres 

 become all tightly matted, or felted together, making a firm, strong piece 

 of cloth. From what has been said, you will see the use of the crimp 

 and the scales of the wool. The crimp makes it possible to twist the 

 wool into yarn which will not easily untwist again, and the scales cause 

 the wool fibres to stick together, or felt. 



It would take too long to describe all the different things that can be 

 made out of wool ; so we shall mention only a few of the principal classes 



Fig. 02.— Wool tilire, 

 sho\vin<r scales. 



