GO 



Solar and Planetary "Evolution. 



the surrounding ring. The spheres formed from the rings 

 would in turn throw off additional rings to form satellites. 



Now, if Ave look at the solar system, Ave discover in its 

 character and movements strong confirmation of this hypoth- 

 esis. We find there just Avhat Avould naturally occur Avere 

 this theory a correct one. Each planet revolves around the 

 central orb at its own speed and in its oavii distinct orbit, 

 and in a direction in common with the rotation of the orig- 

 inal nebulous mass. The nebular theory constitutes there- 

 fore a conclusiA^e and nearly satisfactory explanation of the 

 Avay in which those great demiurgic forces, heat and graA T - 



Fi.e:. 5. 



itation, have Avrought out the results Ave see. In the plan- 

 et Saturn we have an example, patent to any observer, of 

 the probable truth of the nebular theory. (A representa- 

 tion of the planet was thrown upon the screen. See Fig. 4, 

 page 59.) Through any telescope, even of moderate power, 

 Ave may see that this planet is surrounded by rings, which, 

 being nearly equal in density, have not been broken up into 

 satellites by the unequal attraction of their various parts. 

 Though these rings seem solid and uniform through the tel- 

 escope, it is reasonably certain that they are composed of 

 many small bodies, rotating in the same plane, and so pre- 

 senting the appearance of a flat surface. 



