100 Mr. H. Tomlinson. The Influence of 



Table II. 









Velocity of sound 



Metal. 



Condition. 



Density. 



in metres per 







second. 





TJnannealed 



7-7475 



5198 





Annealed 



7 "6831 



5096 





Unannealed 



8-8976 



3958 





5J 



8-6320 



3860 







12-1900 



2804 





J» 



10 -4668 



2801 





5> 



21 '0500 



2750 



In the next table will be found a comparison between the moduli of 

 longitudinal elasticity as obtained by the statical and kinetical 

 methods for steel, copper, platinum, platinum- silver, and silver. All 

 the results given in the table were obtained with as much care as 

 those already quoted. 



Table III. 



Metal. 



Young's 

 modulus in 



grams 

 per square 

 centimetre 

 as obtained 

 by the 

 kinetical 

 method. 



Ditto as 

 obtained by 

 the statical 



method. 



Ditto 

 supposing no 

 heat to be 

 gained or 

 lost dui'ing 

 tbe testing. 



e\. 







2133 xlO 6 



2140 x 10 6 



2144 x 10 6 



-0-0051 





1316 



1323 



1326 



-0-0076 





1622 



1623 



1625 



-0-0018 





997 



1001 



1004 



-0/0070 





8356 



828-6 



831-1 



+ 0-0054 



It will be seen from Table II that the values of Young's modulus, as 

 determined by the statical and kinetical methods, agree with each other 

 Avithin less than 1 per cent., and that on the whole the values obtained 

 by the former of the two methods are slightly greater than those 

 obtained by the latter method.* 



* The author is inclined to attribute this to the fact that with hard-drawn metals, 

 loading always produces a slight amount of temporary twisting. This (see Experi- 

 ment II) tends to produce a slight degree of sticking between the scale and vernier 

 used in the statical method. With well annealed wires this temporary twisting 1 

 does not result from loading. 



