34 



BELL SYSTEM TECHNICAL JOURNAL 



For example we have for quartz at 20° Centigrade 



293 XIO" 



2.65 X 7.37 X 10' 



(14.4 14.4 7.8 -0 0) 



whence </> 



4>: 





 

 

 



862 



For Rochelle Salt we have; 



</> = 



293 X 10" 



1.79 X 15.5 X 10' 



59.9 

 38.1 

 44.8 



4 











(59.9 38.1 44.8 0) 



38.0 24.2 28.5 



24.2 15.4 18.1 



28.5 18.1 21.3 















X 10" 



i 



