Solar and Planetary Evolution. 



63 



of the origin of the solar system. That is precisely what 

 we may observe. (A representation of a nebula in the con- 

 stellation of Lyra was thrown upon the screen. See Fig- 



Fig. 7. Two views of the ring nebula in Lyra 



lire 7.) If we look at this nebula, we find great rifts in 

 it, and brighter spots in some places, which show that there 

 is greater condensation in certain parts than elsewhere. A 

 nebula in the constellation of Leo (shown upon the screen) 

 shows a marked center of attraction, with evidences of a 



Fig. 8. Nebula in Sword of Orion, showing several points of condensation. 



tendency to circular motion. A nebula in Draco (illustra- 

 ted from a photograph taken by Prof. Holden by the aid of 

 the new Lick telescope, the largest in the world) shows a 



