130 CLOTHES AND HOW THEY PROTECT US 



winding together many single wool fibers. The threads and 

 yarns spun from the different fibers are intertwined by weaving, 

 braiding, or knitting, and form the various materials or fabrics 

 from which clothing is made. There are many different kinds 

 of fibers, such as hemp, jute, pineapple, yucca, but the most im- 

 portant fibers used in clothing are 

 wool, cotton, linen, and silk. 



Woolen materials. Wool fibers 

 (Fig. 53) come from sheep and 

 goats ; those fleeced from goats are 

 used to make mohair and alpaca; 

 those from sheep, to make all the 

 other woolen materials familiar to 

 us. Wool is the most valuable 

 fiber in cold civilized countries. 

 Fur is soft and warm and good as 

 an outside covering ; but it is rough 

 and disagreeable when worn next 

 to the skin. 



Wool fibers have scales on their 

 FIG. 53. Wool fibers. i. Al- r , . , , , . 



paca. 2. Camel. 3. Cashmere, surface, which hook into each other, 

 (Courtesy of Philadelphia Com- an( j tne various fibers cling well 

 mercial Museum.) . 



together and are easily woven into 



threads. The fibers vary in length from I to 10 inches ; the 

 longer, coarser fibers are woven into worsted goods ; the shorter, 

 finer fibers are woven into threads from which fine woolen 

 fabrics are made. 



Wool fibers are soft, light in weight, and elastic, and make 

 soft light-weight, flexible, warm garments. They are usually 

 woven loosely, and hence woolen materials are full of air spaces. 

 Air is a poor conductor of heat, and numerous air spaces in a 

 material prevent the escape of bodily heat. Wool, therefore, is 

 an ideal material for cold climates and nothing can take the 



