19 
due to the heat generated by its coalescence, which must have 
been much greater than that produced in Jupiter, whose orbit is 
much smaller. (4) Venus, whose irregularity is slight. 
The distances of the planet are approximately represented 
by the regular series of numbers known as Bode’s Law. If the 
actual distances be reduced in the same proportion, so that the 
number for Neptune is the same as in Bode’s Law, and the two 
sets of numbers be compared, it will be found that all the 
deviations from Bode’s Law are outward, which the attraction of 
the outer planets would account for. In the case of the Asteroids 
the deviation of the outermost is 57° outward, while the inner- 
most has no deviation to speak of. This is significant, and it 
would seem that the enormous attraction of Jupiter broke up the 
next ring, and instead of one planet a large number of small 
planets with intersecting orbits were formed. The next planet 
with marked deviation is Venus, this being probably due to the 
combined attractions of Jupiter and the Earth. Planetary attrac- 
tion cannot, however, explain the high deviation of Uranus. 
Owing to the increasing obleteness of the Nebula as time 
went on, the thickness of the successive rings must have been 
greater in the direction of the equatorial plane in comparison to 
the thickness in a direction vertical to it, but the problem is 
further complicated by the masses and magnitudes of the rings. 
The tendency of a comparatively flat ring would be to form a 
planet with slight axial inclination. So far as these inclinations 
are known, fact agrees with theory, except in the cases of Neptune 
and Venus. 
Rate of rotation, 7.e., the length of a planet’s day, would 
depend upon the difference in velocity between the outer and 
inner parts of the ring, and the planets whose rate of rotation is 
known, have a length of day in excellent accord with mathematical 
calculations. 
The contraction of the Nebula would in all probability 
produce a periodic oscillation of its axis in addition to rotation ; 
the original rings being thus detached at various angles to the 
plane of the Nebula’s equator, the present inclinations of the 
orbits to the ecliptic would be accounted for. This explanation 
is, however, insufficient with regard to some of the minor planets 
e.g., Pallas, with an inclination of 34° to the ecliptic, and there is 
a further difficulty at present unexplained, viz.: how is it that 
Jupiter’s attraction has not yet dragged these asteroids into a 
more level position. 
The retrograde motion of the satellites of Uranus and 
Neptune is probably accompanied by a similar motion on the 
part of their primary. This peculiarity seems difficult to account 
for, but calculations show that the rings of these two planets 
must have been very thin and belt-like, and a retrograde motion 
