336 



THE BELL SYSTEM TECHNICAL JOURNAL. MARCH 1952 



__^__^ i ^ ; ^___^_a ===^ 2000 < 



15 20 



TEMPERATURE 



25 30 35 



DEGREES CENTIGRADE 



Fig. 12 — Temperature variation of crystal constants A'l and iv^ at 80 kc be- 

 fore and after adding weights to mounting wires. 



harmonics. In this way, and m about 30 sec a balance can be conven- 

 iently achieved and the requii"ed ten-fold gam in accuracy attained. 



By these means, and with best literature values of viscosity and 

 density (which were checked m the laboratory at several temperatures) 

 for purified solvents, curves for Ki and K2 were obtamed as exhibited 

 in Fig. 12 for 80 kc. Behaviour of Ki at different frequencies over a tem- 



1500 



45 



50 



5 10 15 20 25 30 35 40 



TEMPERATURE IN DEGREES CENTIGRADE 



Fig. 13 — Temperature variation of crystal constant Ki over a frequency range 

 with benzene and cvclohexane as standard fluids. 



