GRAVITATION VERSUS INERTIA 21 



dament al law be discovered. Yet not only is this 

 miracle true of two cases in the solar system; it is true 

 of the entire eight. All the primary planets revolve 

 in approximately circular orbits, in nearly the same 

 plane, in the same direction (from west to east) and at 

 speeds bearing an exact relation to each other. Most 

 remarkable still is it, that the satellites revolve around 

 their respective primaries according to equally uniform 

 laws, and the planets themselves "rotate" in the same 

 direction as their orbital revolution ! How can mere 

 chance account for these marvels 9 



To sum up, the Projectile theory holds in effect* 

 That the planets are revolving around the sun ? and 

 rotating on their axes, from the effects of a force or 

 forces the origin and nature of which are not only un- 

 known but uuguessable, and which millions of years ago 

 ceased to act; that they travel through a medium of 

 ghost-matter invented for the purpose; that they can 

 change their courses and bear loads without loss of 

 momentum : that they have marvelously happened to 

 ally themselves to the same sun, to have hit upon 

 approximately the same plane, to be traveling in the 

 same direction, to have velocities bearing a fixed ratio 

 to each other; and, finally, that/after millions of years, 

 no accidents have happened to any of them, by meteoric 

 collisions or otherwise, to disturb this singular corre- 

 spondence! But the gravest objection of all to this 

 theory Is th'it it commits the philosophical folly of dar- 

 ing to marry, in undivorcible union, a visionary, fortui- 

 tous, finite, nnaugmentable, and wasting force y to that 

 of centripetal gravitation, which is in all things pre- 

 cisely -what the other is not. 



But why has the theory been so long accepted and 

 implicitly believed in? The answer is simple, and lies 

 in the nature of man himself, who finds in faith of 



