264 SEE— THE NE\V COSMOGONY. [April 21. 



iitciit characteristic of the planets and satellites. The solution thus 

 possesses all the rigor of a theorem in geometry, and meets the 

 requirements of the most rigorous of the mathematical sciences. 



11. The existence of planets beyond Neptune is indicated by the 

 extreme roundness of Neptune's orbit; for this shows that the 

 nebulosity was much too dense at that point for the system to ter- 

 minate at the present known boundary. Moreover, as I have shown 

 that the planets were originally connected with the comets, and the 

 comets recede to their home in a spherical shell thousands of times 

 the earth's distance from the sun, it necessarily follows that our 

 planetary system extends on almost indefinitely. Several planets of 

 considerable size must be assumed to revolve beyond Neptune, and 

 they may yet be discovered by observation or photography, though 

 at that great distance the practical difiliculties will increase, owing to 

 the feebleness of the sun's light and the slow orbital motion, which 

 will require exposures of the photographic plate extending over 

 many hours, and perhaps on successive days. 



12. The planets have been built up out of cosmical dust, comets 

 and satellites ; so that all the matter now in the planets come origi- 

 nally from the heavenly spaces. This follows from the fact that 

 the nebular development is from the outside toward the center, the 

 formation always beginning in the distance and proceeding by accre- 

 tion as the bodies gravitate towards the sun, and revolve in ever 

 smaller and rounder orbits. This order of development is directly 

 verified by the phenomena of the spiral and ring nebulae; for here 

 the movement is proved to be towards the center, where the sun 

 develops for the domination of the system. 



13. And just as our planets have been added onto the sun from 

 without, not thrown olT, as was erroneously taught for more than a 

 century by Laplace and his successors, so also will similar planets 

 have been formed by the same process about the other fixed stars. 

 Thus there are undoubtedly systems of planets about the fixed stars, 

 and they are habitable and inhabited like those revolving about 

 the sun. Moreover, the other suns have their systems of comets, 

 and their planets have captured systems of satellites as in our plane- 

 tary system. This grand conclusion rests on an incontestable basis 

 and is of transcendent philosophic interest. 



