268 
Proceedings of the Royal Society of Edinburgh. [Sess. 
I have shown in a paper on the “ Influence of Twist on the Strength of 
Threads ” * that a thread has much the same strength throughout the first 
turn per inch or so of twist, and afterwards becomes rapidly stronger. 
The difference of the readings on the twist dial, with probably a turn per 
inch added, would give the degree of twist in the thread. This method is 
not nearly so accurate as the first described, because the period of approxi- 
mately constant strength may vary from a half to even two turns per inch, 
depending on the various properties of the yarn. The weight of lever F 
would require to be adjusted so as to produce the breaking tension for the 
untwisted thread, and no more. 
The author has pleasure in acknowledging his indebtedness to the 
Carnegie Trust for the Universities of Scotland for financial assistance in 
this research work. 
* Proc. Roy. Soc. Edin ., 1907, vol. xxvii., part. iii. 
(. Issued separately October 2, 1907.) 
