356 SEE— ORIGIN OF ZONE OF ASTEROIDS. [November 4. 



If we compute the densities of the sun when expanded to fill the 

 orbits of the planets, and of the several planets when expanded to 

 fill the orbits of their respective satellites, we shall get the results 

 given in the last column of the table. In considering this table it is 

 sufficient to recall that an atmospheric pressure of o.i of a milli- 

 meter or a density of 1/7,600 that of air is a very high vacuum; 



Fig. I. Illustration of the motion, of a particle projected along the inner 

 edge of Saturn's dusky ring with velocity corresponding to planet's axial 

 rotation when expanded to fill the ring. Pointed circle shows present dimen- 

 sions of planet. 



and since no greater hydrostatic pressure than this could be exerted 

 from the center outward in case of most of the planets and many 

 of the satellites as they fall unsustained by centrifugal force towards 

 their dominant central masses, we see that these attendant bodies 

 would in all cases fall practically without obstruction, and collision 

 would in every case occur at the end of half a revolution. Could a 

 more complete overthrow of the traditional detachment hypothesis 

 of Laplace be imagined ? 



10. This affords an impressive illustration of the fallacy of the 

 Laplacean theory of the origin of the planets and satellites; and 



