STRENGTH OF FIBER 



315 



Uniformity. A fleece is uniform in fineness when all the fibers 

 are about the same in diameter. It is practically impossible to get 

 absolute uniformity in this respect throughout the fleece and it is 

 not expected. The wool on the. hips seldom equals that on the 

 shoulder in fineness, but the variation in the wool grown on these 

 two regions of the body is much less in some individuals than 

 in others., and when this is the case, the fleece as a whole is much 

 more nearly uniform in quality. 



Strength of Fiber. ^Wool is regarded as strong when individual 

 fibers do not have a weak place somewhere in their length. These 

 weak places are due largely to periods of sickness and undernourish- 





FIG. 197. Kemp, structureless like fibers that are brittle and do not take the color 

 dyes^ .A, longitudinal section^ B, cross-section, compare with Fig. 24. (From "Structure 



s. A, longitudinal section, B, cross-section, compare 

 Wool Fiber," Bowman. Courtesy of The Macmillan Co.) 



ment, or to abrupt changes from dry to green feed, or vice versa, 

 while the sheep is growing the wool. Hence, strength of fiber is 

 a factor which depends more or less upon good feeding and shep- 

 herding; and the kind of care necessary to produce a good crop 

 of lambs is the best for growing wool. Tender wools, especially 

 if they are two and one-half inches or more in length, sell for less 

 than wools of similar length and finish because they break in the 

 process of combing and must be used as short wools. 



It is often possible to see the weak or tender place or to deter- 

 mine its location by pulling on a lock of wool and noting where 

 it breaks. Such a test is only an approximation of whether the 



