of the double refraction in strained glass. 



325 



A. 



Table IV. 103. 

 B. 



C. 



Remarks on O 103. 



A. April 6. No diaphragm used. Double prism in spec- 

 troscope. 



B. April 7. Narrow central diaphragm. Double prism. 



C. April 8. Central diaphragm. Single prism. 



[A. and B. are the only two sets of observations for which the 

 two prisms were used. 



The band for first extinction was the only one observed.] 



