ass, "all probability would be in favour of
its breaking up into many masses." This alternative result certainly
seems the more likely. But granting that a nebulous ring would break up
into many masses, it may still be contended that, since the chances are
infinity to one against these being of equal sizes _and_ equidistant,
they could not remain evenly distributed round their orbit. This annular
chain of gaseous masses would break up into groups of masses; these
groups would eventually aggregate into larger groups; and the final
result would be the formation of a single mass. I have put the question
to an astronomer scarcely second in authority to the one above referred
to, and he agrees that this would probably be the process.]

[Footnote 18: The comparative statement here given differs, slightly in
most cases and in one case largely, from the statement included in this
essay as originally published in 1858. As then given the table ran
thus:--

Mercury. 1/362
Venus. 1/282
Earth. 1/289 1 Satellite.
Mars. 1/326
Jupiter. 1/14 4 Satellites.
Saturn. 1/6.2 8 Satellites, and three rings.
Uranus. 1/9 4 (or 6 according to Herschel).

The calculations ending with these figures were made while the Sun's
distance was still estimated at 95 millions of miles. Of course the
reduction afterwards established in the estimated distance, entailing,
as it did, changes in the factors which entered into the calculations,
affected the results; and, though it was unlikely that the relations
stated would be materially changed, it was needful to have the
calculations made afresh. Mr. Lynn has been good enough to undertake
this task, and the figures given in the text are his. In the case of
Mars a large error in my calculation had arisen from accepting Arago's
statement of his density (0.95), which proves to be something like
double what it should be. Here a curious incident may be named. When, in
1877, it was discovered that Mars has two satellites, though, according
to my hypothesis, it seemed that he should have none, my faith in it
received a shock; and since that time I have occasionally considered
whether the fact is in any way reconcilable with the hypothesis. But now
the proof afforded by Mr. Lynn that my calculation contained a wrong
factor, disposes of the difficulty--nay, changes the objection to a
verification. It turns out that, according to the hypothesis, Mars
_ought_ to