28 
BULLETIN 1488, U. S. DEPARTMENT OF AGRICULTURE 
cloth is probably due to the fact that fibers are transparent after 
mercerization, hence some of the light is absorbed instead of being 
reflected (fig. 18). 
The strength of the gray cloth fillingwise tends to follow the 
strength of the gray yarns. The strength of the latter is greater 
because more twist was inserted in the warp yarn and more threads 
were tested in each instance (fig. 19). 
STRENGTH 
IN POUNDS 
90 
Siren 
_ 
/ Warp Yarn ( 
^ 
J^ 
Sh 
-enqlh of Cray 
Cloth (inch wio 
fh. Filling Direction )-^ 
60 
70 
60 
9 8 7 65 ^32 
GRADE NUMBERS 
Fig. 19.— Strength of gray cloth compared with gray warp yarns spun from the same grades. 
(Average of eastern and western.) The strength of the gray cloth fillingwise tends to follow 
the strength of the gray warp yarn from the same grade 
SUMMARY 
These spinning tests were conducted to determine the relative 
intrinsic value of each of the nine white grades of American upland 
cotton. 
For comparative purposes all grades were run under similar 
mechanical and moisture conditions. 
The average percentages of visible waste from the nine grades of 
cotton representing the universal cotton standards, when run under 
these conditions ranged from 5.50 per cent on grade No. 1 to 14.44 
per cent on grade No. 9. (See Table 4.) 
The strength of the yarn did not always follow the grade of the 
cotton, but there was a tendency for the higher grades to produce 
stronger yarns. Bleached yarns of all the grades were weaker than 
the corresponding gray \arns, whereas the mercerized yarns were 
stronger. The strength of these finished yarns followed closely the 
strength of the gray yarns. 
The irregularity of the sizings of the stock in process and of the 
strength and sizings of the yarns was independent of the grade of the 
cotton. Double-bleached yarns were more irregular than single- 
bleached. No marked difference was noted in the regularity of gray, 
single-bleached, and dyed yarns. .. 
A formula has been suggested for estimating the difference in the 
relative values of the grades. 
