PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. *J0S 



mary is, provided the densities are equal. Jupiter is both denser 

 and larger than Saturn ; so that there are, in this case, two reasons 

 why the interval should be greater between Jupiter and lo than 

 betv/een Saturn and Mimas. 



The deductions from the foregoing are : 



1. The hypothesis of Laplace, that increasing centrifugal force 

 threw the exterior rim of the nebula off, is inconsistent with the 

 fact that 667 parts out of 668 are now ifi the sun ; and 439 out of 

 475 parts of the remainder are now in the interior third of the 

 radius of the system, while only 36 parts are in the outer two- 

 thirds. 



2. The nebulous mass in rotation would tend to become an 

 oblate spheroid ; and the most of its matter would be located 

 between the Sun and Jupiter, where there actually is the least 

 matter. 



3. The effect of a resisting etherial medium would be to cause 

 the lightest portion of the nebulous matter to move in spiral paths 

 to the Sun. The matter nearest to the Sun, the orbital motion of 

 which was greatest, would be most affected by the medium. The 

 densities of the pUmets, and the actual distribution of matter in 

 the solar system, and in each system of satellites, is such as this 

 theory requires. In each system there is, first, an immense pri- 

 mary ; second, several small secondaries with narrow intervals, 

 the first interval, however, being greater than the next succeeding 

 one ; third, there is one giant secondary, containing more matter 

 than all the others ; fourth, beyond the giant are one or more 

 secondaries of intermediate size, with very wide intervals. 



4. It Avas long ago noticed that the intervals between the planets 

 and satellites become greater the further they are from the centre, 

 and this fact is represented by what is called Bode's law ; but no 

 reason for the fact has, until now, been discovered. I have found 

 that the differences between the orbital velocities of the seconda- 

 ries, in each system, can be divided by a common divisor without 

 any essential remainder. The divisor in the case of the planets is 

 1,582; of Jupiter's satellites, 808; of Saturn's satellites, 714; of 

 the satellites of Uranus, 600. I account for this fact on the theory 

 tbat the parts of the nebula were held together by an attractive 

 'force, which, in the solar system, it required a difference of orbital 

 velocities equal to 1,582 miles per hour to overcome. On account 

 of the increasing velocities, this difference was obtained with less 

 difference of distance (a narrower interval) the nearer the matter 



