489 



MEASUHEMENTS OF CRYSTALS. 



I 



aUARTZ. (Continned.) 



Figs. 167, 168 and 173, twin crystals. 

 Figs, 174, 175. 



Pono 128°20' 



Fig. 181. 

 P on a? 

 r on 0! 

 X onz 



148042' 

 167 56 

 125 11 



