282 



Prof. J. N. Lookyer. 



[June 21, 



two lines near 4471 and 4481 have approached each other, as they 

 should do if one belongs more especially to R and the other to B. 



6. When the two bodies lie along the line of sight, partial eclipses 

 occur. This happens near the minima of the light curve. 



The differences in the intensities of the dark lines special to R and 

 B, near the two minima, indicate that near the principal minimum K. 

 is partially eclipsed by B, while near secondary minimum B is par- 

 tially eclipsed by B. These changes will be seen on Plate 1, and 

 again in Plate 2. In the latter we have comparisons of ft Lyrae 

 at the two minima with Bellatrix and Rigel. If we leave the bright 

 lines out of consideration, it will be seen that near principal minimum, 



