THE NEBULAR HYPOTHESIS. 651 



Notwithstanding the number of orbs of which the solar system is 

 composed, and the consequent almost infinite variety of their possible 

 dispositions, the following coincidences wholly independent of the ! 

 law of gravitation are found to obtain : 1. The sun rotates on his axis 

 from west to east. 2. All the planets (now 104 in number) revolve 

 about the suu from west to east. 3. All the planets (as far as known 

 rotate on their axes from west to east. 4. All the satellites (excepting 

 those of Uranus and Neptune) revolve about their primaries from west 

 to east. 5. All the satellites (as far as known) rotate on their axes in the 

 same direction in which their primaries turn on their axes. 6. All the 

 planets (with the exception of a few minute asteroids) revolve about 

 the sun, nearly in the plane of the solar equator. 1. All the satellites 

 (as far as known) revolve about their primaries nearly in the planes of 

 the equator of their respective planets. 8. All the planets (with the 

 exception of a few asteroids) have orbits of small eccentricity. 9. All 

 the satellites have, in like manner, orbits of small eccentricity. 



These nine independent coincidences in the arrangements of more 

 than 127 separate bodies, cannot be supposed to be fortuitous they 

 naturally suggest the existence of some grand and comprehensive law, 

 pervading the whole solar system. That they are not consequences 

 of the law of gravitation, is evident from the fact that the comets 

 transgress every one of these laws which could be applicable to them. 

 According to the laws of probability, the chances against the concur- 

 rence of so many unconnected phenomena are almost infinite. Laplace 

 estimated that the chances were four millions of millions to one, that 

 these were not arbitrary acciendtal phenomena. Since his time, facts 

 of a similar bearing have largely accumulated, and the chances against 

 their fortuitous concurrence are now almost beyond the power of num- 

 bers to express. " The coordination of these divers and unconnected 

 phenomena the grouping them into one coherent and harmonious 

 scheme the referring them to one common cause and origin, and 

 thereby imparting to this fair work of the Eternal the semblance of a 

 Unity worthy of a Divine Idea" these were the sublime and lofty 

 aims of the famous " Nebular Hypothesis" of Laplace. He imagined 

 " that this consummate fabric this gorgeous planetary scheme like 

 the blossom, had a bud and deeper yet, that it had a mysterious 

 germ, within which rested the necessities of its present glorious un- 

 folding ! . . . . He sought, by penetrating the deep recesses of the 

 past, to reveal the mystery of its development, and conceived the bold 

 thought of portraying the modus operandi of the genesis of our Solar 

 System." 



In its original form, the Nebular Hypothesis required three assump- 

 tions, viz. : 1. An agglomerated nebulous mass ; 2. That this mass 

 be rotating about its centre of gravity ; and 3. That it be incandescent 

 from excessive heat. The successors of Laplace have endeavored to 

 simplify the hypothesis, by showing that rotation of the nebulous mass, 



