70 Solar <nul Planetary Evolution. 



volve around its gravitational centre. In this continued mo- 

 tion resides the potency of renewed life. Motion is trans- 

 ferable into heat ; and heat calls gravitation into action. If 

 the earth, moving through space at the rate of nearly twen- 

 ty miles a second, should meet another body of like size 

 and velocity, its mountains would dissolve in fiery mist, its 

 oceans would be turned into vapor, its continents would dis- 

 solve in smoke, and the solid earth would melt like wax 

 and disappear in a nebulous cloud. The same would be 

 true of an encounter between the sun and another sun pos- 

 sessing equal mass and equal or greater velocity ; out of 

 the nebula thus formed, through the process of evolution, 

 a new sun might be formed, and new life ultimately dawn 

 on other worlds. The stars are shooting in every direction 

 in erratic courses, and such collisions are not impossible. 

 It is reasonably certain, indeed, that they have occurred. 

 New stars have suddenly appeared, and stars of lesser mag- 

 nitude have blazed up into more magnificent suns. 



The charm of the study of creation, where we behold the 

 gleam of millions of suns, and systems on systems, is not 

 in thinking of our own insignificance in the presence of this 

 wonderful universe ; for we are small only as we identify 

 ourselves with our little earth. We should regard our- 

 selves not merely as citizens of the world, but, with a true 

 cosmopolitan spirit, as citizens of the universe. Matter 

 changes form, but it is not created and it does not die. 

 When the sun is dead and the earth is in darkness, the 

 wheels of life will still run in the light of other suns ; and 

 even our ashes may yet thrill with new life, on a new earth, 

 in the beams of a new sun. 



