222 BELL SYSTEM TECHNICAL JOURNAL 



Differentiating these with respect to t, we have 



T E = T E — 



^ S66 -^ C44 



5ii 



£2 



'"''' -^.(T.f, + T4.)'j+ ^'" 



E E 





BE £2 -^ Ci4 



C44 C66 — Cl4 



^11 — Si2 



T.E — 



^ «11 



-J}1 r^ 



B £ *1 2 



r £ = T E — 



-• sm •' I'm 



r ^^^^^^'g (T E 4- r^)! 



£ E £2 ^.-t C44 T^ -I Csey* 



LC44 C66 — Ci4 J 



+ 



2ci4 



(A.73) 



T E 



E E £2 -^ Ci4 



C44 C66 — ^14 



r.^ = TrE — 



C44 Cfif 



** ^ (T-.f. + r.f.)] + ^'' 



£2 



- T E 



C44 C66 Cl4 



E B E''- '^\i 



Cii ^66 — Cl4 



Table VII 



Inserting the numerical values for the elastic constants and the tempera ure 

 coefficients we have 



r.f, = .883r,f, + .io7ir,f, = -134.5; t,e^ = 121.4; 



r.f, = 195.4 



(A.74) 



