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Proceedings of the Royal Society of Edinburgh. [Sess. 
of large oscillations it seems to rise at first and then fall. Generally 
speaking, the results are similar to those found by Mr Ritchie in the case 
of brass wire. 
Diagram II. gives a few of the observed data at the temperature 500° C. 
The circles refer to the duplicate experiment. 
(v.) Finally, the same wire which had been heated was placed in liquid 
air for half an hour, and the following were the results : — For large 
oscillations, a — 1, n = *089 ; for small oscillations, a — 11, n — - 014. Thus the 
cooling of the wire practically left the constants unchanged. 
The apparatus used for producing the rotational and extensional strains 
was described by Mr Ritchie, Proc. Roy. Soc. Edin., 1910-11, p. 440, and 
was constructed for Dr Peddie by means of a Royal Society grant. 
( Issued separately July 11 , 1912 .) 
