Apr. 15, 1920 



Influence of Humidity upon Wool Fiber 



57 



while samples 994, 996, and 997 had an average diameter of 0.026, 0.029, 

 and 0.025 mm., respectively. There was one sample of wool with an 

 average diameter of fibers less than 0.02 mm., and there were three sam- 

 ples with the average diameter above that figure. 



The new set of samples chosen, A, B, C, and D, consisted of four samples 

 with average diameters of 0.012, 0.018,0.017, and 0.031 mm., respectively. 

 Three of these samples were under 0.02 mm. in diameter, and one 

 was larger. The range in average diameter of the fibers tested is from 

 0.012 to 0.031 mm. Fibers were tested from small locks of scoured 

 wool from samples A, B, C, and D until 200 fibers were tested at each of 



-/-^ 



2^ 



-5^ SO GO 70 <90 



Fig. 2.— Graphs showing the effect of humidity upon the elasticity of wool fiber. 



five humidities, as shown in Table III. It will be noted that the break- 

 ing strength of the fibers decreases quite uniformly as the humidity 

 increases. Sample D shows a decrease in its tensile strength as the 

 humidity increases up to 80 per cent, when there is a very slight increase. 

 In A, B, and C the tensile strength seems to fluctuate up and down with 

 no particular uniformity. These values for tensile strength were much 

 more variable than those for the breaking strength. Several hundred 

 additional fibers were tested on A, B, C, and D at humidities of 40 and 

 50 per cent, since the greatest variability seemed to occur at these two 

 points. Graphs showing the values obtained on these samples of scoured 

 wool for breaking strength and elasticity are shown in figures i and 2. 



