18 
BULLETIN 882, U. S. DEPARTMENT OF AGRICULTURE. 
Table 13. — Results of tests oy the Signal Corps and the Bureau of Markets on 
2/60's cotton airplane faoric. 
Stretch in 
inches at different loads. 
Breaking 
strength. 
Key 
Construction. 
Tested 
by- 
Oz. 
or 
sam- 
ple. 
No. 
Warp. 
Filling. 
Warp. 
Fill- 
ing. 
per 
10 lbs. 
20 lbs. 
70 lbs. 
10 lbs. 
20 lbs. 
70 lbs. 
7 
2/60's 80 by 80 plain 
weave, made from 
Lbs. 
87 
89 
Lbs. 
89 
88 
No. 1 (fancy) Pima 
American Egyptian 
mercerized yarn. 
M.... 
S. C. . 
0.53 
.46 
0.75 
.64 
1.20 
1.04 
0.19 
16 
0.30 
.26 
0.62 
.51 
} 4.23 
Single twist, 30.5; 
ply twist, 21.5. 
21 
2/60's 80 by 80 plain 
weave made from 
Sea Island mercer- 
zed yarn. Single 
M.... 
'S. c. 
.48 
.52 
.66 
.73 
1.03 
1.07 
.19 
.28 
.29 
.41 
.54 
.81 
85 
88 
91 
93 
},0 
twist,30.5; ply twist, 
21.5. 
2/60's 80 by 80 plain 
32 
weave made from 
high-grade S a k e 1 . 
M.... 
.32 
.49 
.83 
.20 
.27 
• 50 
98 
100 
\ 4.15 
mercerized yarn. 
S.C.. 
.46 
.66 
.96 
.25 
.34 
.55 
98 
97 
Single twist, 30.5; 
ply twist, 21.5. 
33 
2/60's 80 by 80 plain 
weave, made from 
lower grade Sakel. 
M.... 
.40 
.61 
1.00 
.18 
.27 
.51 
90 
99 
| 4.22 
mercerized yarn. 
S.C.. 
.62 
.84 
1.19 
.21 
.30 
.50 
93 
98 
Single twist, 30.5; 
ply twist, 21.5. 
M=Bureau of Markets; S. C. = Signal Corps. Twist is stated in turns per inch of yarn. 
Tmportant results obtained by the Signal Corps on the 15 fabrics 
(see Tables 12 and 13) are shown in several graphs reproduced be- 
low. These graphs are copies of those produced by the stretch 
recording device on the automatic cloth-testing machine of the dead- 
weight type used in all of the tests by the Signal Corps. The effect 
of mercerization may readily be seen by a comparison of figures 1 and 
2, which relate, respectively, to gray and yarn-mercerized fabrics as 
represented by key or sample numbers 1 and 2, and of figures 3, 4, 
and 5, which relate, respectively, to gray, yarn-mercerized, and piece- 
mercerized fabrics as represented by the key numbers 8, 9, and 11. 
The stretch figures of the Signal Corps given in Tables 12 and 13 
were obtained from the graphs, the point where the graph leaves the 
vertical line on the left being considered the origin of coordinates. 
This assumption was followed in all of the Bureau of Markets' tests, 
as it is obvious that until the line leaves the vertical there is no load 
sustained. This eliminates inconsistencies due to inserting the sam- 
ple between the jaws at different degrees of tension or tautness. No 
comment upon the Signal Corps graphs is necessary other than to 
state that in general they followed very closely the results obtained 
in the tests made by the Bureau of Markets. (See Tables 12 and 13 
for comparison.) Figures 6, 7, and 8, which relate to fabrics repre- 
sented by the key numbers 7, 21, and 32, respectively, illustrate the 
