1906-7.] 
257 
The Strength of Twisted Threads. 
TABLE III. 
Relation of Strength to Twist in Two-ply Threads. 
Turns 
per inch 
of 
Two-ply 
Twist. 
Load in lbs. on the Thread at the Yield Point. 
2/16’s Botany. 
2/12’s Crossbred. 
30/30 Saxony. 
56/56 Saxony. 
0 
•96 
1-43 
•73 
•44 
1 
•98 
1-44 
•75 
•45 
2 
1-07 
1-54 
•78 
•51 
3 
1-15 
1-64 
•81 
•56 
4 
1-21 
1-71 
•85 
•60 
5 
1-27 
1-77 
•87 
•63 
6 
1-32 
1*82 
•92 
•65 
7 
1-35 
1-86 
•95 
•67 
8 
1-38 
1-89 
•98 
•69 
9 
1-41 
1-92 
1-00 
•70 
10 
1-43 
1-94 
1-02 
•72 
11 
1-44 
1-96 
1-05 
•74 
12 
1*47 
1-97 
1-06 
•75 
13 
1*48 
1-97 
1-08 
•76 
14 
1*49 
1-98 
1-10 
•77 
15 
1-50 
1-98 
1-11 
•78 
16 
1-51 
1-12 
•79 
17 
1-51 
•80 
18 
1-52 
•80 
19 
... 
•81 
20 
•81 
21 
•82 
22 
•82 
| 
One reason that the inflection in the graph for the 30/30 yarn is less 
pronounced than in the other graphs is that the thread was very elastic 
and stretched considerably up to the yield point. Thus the/method used is 
not very accurate for yarns of this description. 
Table IV. shows the ultimate breaking loads of the smallest possible 
length of each yarn which can be placed between the jaws of the testing 
machine. This length may be taken as 1 millimetre. 
TABLE IV. 
Breaking Loads of 1 mm. of Yarn. 
Single Threads. 
Two-ply Threads. 
6’s Worsted 
2-32 lbs. 
2/16’s Botany 
1*79 lbs. 
7-cut Cheviot 
4-15 „ 
2/12’s Crossbred 
2*66 „ 
10 „ 
2-42 „ 
30/30 Saxony 
1-36 „ 
„ „ 
P26 „ 
56/56 
1-05 „ 
VOL. XXVII. 
17 
