132 FROM NEBULA TO NEBULA 



Even though the bores, or calibers, of planetary 

 spirals admittedly exhibit elliptical curvatures, the fact 

 conveys little hint of the dynamical agencies concerned in 

 their generation. Profoundly interpreted, each infinites- 

 imal arc in each and every one of the planetary- and 

 satellite spirals is a coordinated resultant of the equili- 

 bristic adjustments of the aggregate system; that is to 

 say, every movement and turn of movement of the planets 

 is a concomitant effect of each member balancing itself 

 against all the rest. The solar system, in fine, is essen- 

 tially a revolving, composite lever. To preserve the com- 

 mon equilibrium, when one member moves out from the 

 sun another or others must, perforce, move in, and vice 

 versa. These compensations automatically follow from 

 the principle of balance, and extend to every part, even 

 to the molecules and atoms that hang suspended in space ; 

 even, indeed, to the ether itself, if it be amenable to grav- 

 ity. These compensating pulsations of the planets in and 

 out from center have not escaped the keen eyes of astron- 

 omers, and have led to the empiricism and near-truth that 

 the moment of momentum of the system preserves its uni- 

 formity. Unknowing the dynamical cause behind the 

 phenomenon, they construe it as a teleological ordination, 

 and point to it as the unimpeachable evidence of the so- 

 called doctrine of the conservation of energy. 



The fact that the planets have accommodated them- 

 selves all to practically one plane (that is, to a position of 

 ' ' flatness "), which, as I have shown before, is the condi- 

 tion of maximum stability, joined to that other significant 

 fact that their orbits are near-circles, demonstrates 

 either ; first, that the planets are direct offsprings of the 

 sun, or, second, that they have been members of the sys- 

 tem so inconceivably long as to be in effect indigenous to 

 it. It is otherwise with the comets and many of the as- 

 teroids, whose eccentricities of elongated orbits, high in- 

 clinations and retrograde motions are so many unmistak- 

 able proofs of their alien parentage and comparatively 

 recent immigration. Like the bubble of a spirit level 

 when first applied in test, a comet takes a series of pulsa- 



