NEBULAR THEORY OF THE UNIVERSE. 



41 



manifestly volcanic, lava currents being distinctly visible. 

 We see in fact a torn, rugged, sterile area, studded with 



Lign. 3.— Telescopic view of the moon. 



craters, and scarred by rents and chasms, and having such 

 an aspect as we may conceive would be presented by our 

 earth, were the pinnacles of the granite mountains un- 

 abraded, and the valleys bare, and not covered and partially 

 filled up by sedimentary deposits.* But there is no evi- 

 dence of the presence of either air or water in the moon. 



12. Nebular theory of the universe. — In the 

 original condition of the solar system, it is supposed that 

 the sun was the nucleus of a nebulosity, or luminous mass, 

 which revolved on its axis, and extended far beyond the 



* See Appendix A. 



