78 



BELL SYSTEM TECHNICAL JOURNAL 



RIGHT HANDED 

 CRYSTAL 



X (+BY COMPRESSION 



Fig. 2 — Diagram illustrating angles used in expressing orientation oi AT and BT 

 plates within the natural crystal. 



-75 -60 -45 -30 -15 15 30 45 60 7! 



ANGLE OF ROTATION ABOUT X AXIS IN DEGREES (e) 



Fig. 3 — Temperature coefficient for thin plates plotted as a function 

 of the angle of cut. 



