MANUFACTURING TESTS OF COTTON 
11 
the average of grades 1 and 2 exceeded the strength of the new 
Draper standard for 22s carded warp yarn. 
Figure 4 shows that there is less variation in average strength of the 
several grades from the best representative line than is shown in 
POUNDS 
PER 
SKEIN 
70 
*" 
s 
-3- 
/ 
/ New 
Draper Stonda 
. _ _ 
rd ^ 
•»» w 
^ 
III ~^'"lll " 
k4/-™ 
V 
6 
5 4- 
GRADE NUMBERS 
Fig. 3.— Strength in pounds per skein of 22s gray warp yarn spun from western upland cotton. 
The crosses on the dash line indicate the average strength obtained from 72 observations, while 
the solid line " A " is the best representative line. Note the tendency for the strength to increase 
as the grades vary from No. 9 to No. 1. (See Table 8.) 
either Figure 2 or Figure 3. This greater uniformity or decreased 
variation from the trend line is due mainly to the fact that a greater 
number of bales was used. The result for each grade was obtained 
5 4 
GRADE NUMBERS 
Fig. 4.— Average strength in pounds per skein of 22s gray warp yarn spun from eastern and western 
upland cotton (average of results shown in Figs. 2 and 3). The variation of the plotted data 
from the best representative line "A" is less than in either Figure 2 or Figure 3. The strength 
has a tendency to increase from grade 9 to grade 1 
from 144 observations, 72 eastern and 72 western. This is permissible 
since the same number of bales w T as used in the case of the eastern as 
in the western cotton. In commercial mills this greater uniformity is 
