58 Mr. Smith on the Planet Saturn. 
pears the simplest thing imaginable; for I think it self-evident 
that if the ring were removed to a distance of two or three 
millions of miles from the planet and left at liberty, it must by 
its own gravity fall towards the planet ; and after perhaps im- 
pinging thereon, it must continue to fall until its centre of gra- 
vity coincides with that of the planet: in which case the planet 
must of course occupy its centre. Now, if Saturn were a sphere, 
the ring might assume any accidental position with respect to 
the equator of the planet; but by reason of the spheroidal figure 
of Saturn occasioning an excess of gravity towards its equa- 
torial regions, the plane of the ring must be drawn into the 
plane of Saturn’s equator, which is exactly the situation in 
which we find it: the rotation of the ring on its axis is, there- 
fore, unnecessary to its support. 
A very curious subject for speculation, which does not ap- 
pear to have hitherto suggested itself to the inquiry of astrono- 
mers, is the following: What is the use of this stupendous ring, 
which for extent of surface and solidity of structure (as we 
may infer from its superior brightness) surpasses even the 
planet itself? Can it be a habitable world ? Certainly it may; 
for the velocity with which the ring revolves on its axis may 
be so adjusted as to produce a centrifugal force which shall 
be an exact counterpoise to the force of gravity towards the 
planet: and in such case the surface of the ring must appear 
to the annularians as a horizontal plane; while the body of the 
planet is seen in the distance like an immense mountain, be- 
hind which the sun disappears for about one or two hours 
(according to circumstances) out of every ten hours, or one re- 
volution of the ring. The edges of the ring are probably 
rounded off, although our instruments will not enable us to 
verify this fact by observation ; and in such case the annularians 
may travel either by land or water from one surface of the 
ring to the other without observing any remarkable appear- 
ance, except that on passing round the edge of the ring the 
heavenly bodies will change their altitudes rapidly within a 
comparatively small space. To those who may be on the in- 
ner edge of the ring the body of the planet probably appears 
as a circular plane directly over their heads, and supported by - 
ps eae pillars rising from opposite points of the horizon. The 
satellites of Saturn are probably never seen by the annularians, 
except by those who may be near the outer edge of the ring ; 
for as they revolve in the plane of the ring, they are always in 
the horizon: the seventh satellite is, perhaps, an exception ; 
for as it deviates from the plane of the ring, it may occasionally 
appear a few degrees above the horizon. 
It has been conjectured by some who have thought but 
slightly 
