390 



KNOWLEDGE. 



October, 1913 



Figure 406. Halo obtained with X-rays without crystal. 



Figure 409. Spots from mica normal to rays. 



• 



k 





Figure 407. Halo from metals without crystals. 



Figure 410. Reflection from mica at angle 85° showing 

 bands on the reflection and intermediate band. 



Figure 408. No crystal used. Showing a broad white 

 band across plate ; also black bands. 



Figure 411. Shows peripheral effects with mica across 

 aperture in metal screen. 



