Smithsonian Report, 1916. — Abbot. 



Plate 5. 



The Pleiades. (G. W. Ritchey.) 



Photographed with the 2-foot reflector of the Yerkcs Observatory . 1901, October 19. 

 Exposure S'^ hours. Cramer Crown plate. From "The Suu," by G. C. Abbot. 

 Published by Appleton & Co., 1911. 



