CARNEGIE INSTITUTION OF WASHINGTON 



PUBLICATION No. 255 



NOTE. 



The eleven departments of research of the Carnegie Insti- 

 tution of Washington, of which the Mount Wilson Solar 

 Observatory is one, are located in various places selected 

 because of their suitability for the several purposes in view. 

 Information regarding the work of the Institution may be 

 obtained on application to the Office of Administration, 

 Washington D. C. 



33 



GIBSON BROTHERS, PRINTERS 

 WASHINGTON, D. C. 



