126 FROM NEBULA TO NEBULA 



mutual attractions, and so distantly removed from the 

 stars in general, as to behave as a consolidated mass in 

 this : that, while in the act of falling in the direction of 

 the resultant of the stellar attractions, they seek their 

 common systemal center of gravity and revolve around 

 each other according to the 



LAW OF THE LEVER OR BALANCE ARM 



It is a fact already well recognized by astronomers, 

 that the moon does not revolve around the center of the 

 earth, but around the center of gravity of their joint 

 mass, and that a similar principle holds good of the 

 planets with respect to the sun. So far, then, the princi- 

 ple of the balance arm has been scientifically accepted. 

 But this knowledge does not dispose of the riddle as to 

 why these bodies rotate at all ; it does not explain the im- 

 pulsion that lay, or lies, behind those tangential or cen- 

 trifugal motions, nor does it point out what keeps them 

 going. My conception is, that the orbital movements of 

 the circulating bodies is due to their act of falling at the 

 command of the Prime Eesultant, and that instead of 

 falling down in straight lines, as they would do were their 

 mutual attractions dissolved, they fall with a spiral twist 

 that carries them perpetually round and round their com- 

 mon center of gravity. In short, the solar system, I hold, 

 is an immense clock driven by its own descending weight. 



In order to get as clear a notion as possible of the 

 torsional effects of the stellar attractive forces, let us re- 

 call the little laboratory experiment we tried before with 

 the yardstick and the strings. But suppose now, that 

 instead of using the ring, you twist the strings round and 

 round one another at the point where the ring was, and 

 then do you and I pull as before. In such case, the rod 

 will be seen to make numerous revolutions, as many, in- 

 deed, as there were windings to the strings. 



Now, it is impossible for us, here on earth, to repro- 

 duce in all respects an imitation of the gyrations of the 

 solar system in free space. We are endowed, however, 

 with human intelligence, which ought to enable us to rea- 

 son these things out for ourselves. Imagine, then, two 



