47 



FIG. 36. The Great Nebula in Andromeda. 



We are thus prepared to appreciate the intimate 

 relationship which unites all phases of the Observa- 

 tory's work and determines its plan of operation. 

 But how shall we enter the vast sphere of the 

 sidereal world, where hundreds of millions of 

 objects, exhibiting phenomena of inconceivable 

 magnitude and infinite variety, vie with one an- 



