255 
1906-7.] The Strength of Twisted Threads. 
apparatus was not always quite steady in its action, and the can E, being of 
considerable cross section, did not lend itself to accurate reading of the 
volume of water at each yield point. 
The following Table (II.) shows the results for the following single 
threads: 6’s crossbred worsted; 7-cut woollen, spun from crossbred lamb’s 
wool ; 10-cut and 16-cut woollen. The worsted thread was composed of 
very long, straight fibres, while the three Cheviot woollen threads were of 
the soundest and most uniform quality. The cut system of numbering 
used in this paper is that of Galashiels, viz. the number of cuts of 300 
yards each which weigh 1J lbs. is the yarn number. This system is now 
used largely in Scotland and Ireland for woollen yarns. 
TABLE II. 
Relation of Strength to Twist in Single Threads. 
Turns 
per inch 
of Twist. 
Load in lbs. on the Thread at the Yield Point. 
6’s worsted. 
7- cut. 
10- cut. 
16-cut. 
0 
•04 
•08 
•04 
•06 
1 
•06 
T5 
•05 
•12 
2 
•26 
•56 
•08 
•26 
3 
•60 
1-67 
•17 
•40 
4 
•99 
2-28 
•36 
•51 
5 
1-21 
266 
•60 
•61 
6 
1-36 
2-82 
•82 
•68 
7 
1-46 
2-92 
1-05 
•72 
8 
1-51 
2-98 
1-11 
•76 
9 
1-54 
3-02 
1-15 
•80 
10 
1-62 
1-20 
•84 
11 
1-65 
1-26 
•88 
12 
1-69 
1-32 
•91 
13 
1-72 
1-35 
•94 
14 
1*75 
•96 
The results of Table II. are shown graphically in fig. 4. The loads at 
the yield points are plotted as ordinates, the corresponding turns of twist 
as abscissae. 
Table III. shows the results for the following two-ply threads: 2/16’s 
Botany worsted, 2/12’s crossbred worsted, 30-cut two-ply Saxony woollen 
(scoured), 56-cut two-ply Saxony woollen (greasy). 
The results of Table III. are shown graphically in fig. 5. The loads at 
the yield points are plotted as ordinates, the corresponding turns of twist 
as abscissae. 
