one belief that he cannot
call upon his telescope to substantiate. He thinks that all the myriad
suns of his numberless systems are instinct with life in the human
sense. Giordano Bruno and a long line of his followers had held that
some of our sister planets may be inhabited, but Herschel extends
the thought to include the moon, the sun, the stars--all the heavenly
bodies. He believes that he can demonstrate the habitability of our own
sun, and, reasoning from analogy, he is firmly convinced that all the
suns of all the systems are "well supplied with inhabitants." In this,
as in some other inferences, Herschel is misled by the faulty physics
of his time. Future generations, working with perfected instruments, may
not sustain him all along the line of his observations, even, let alone
his inferences. But how one's egotism shrivels and shrinks as one grasps
the import of his sweeping thoughts!

Continuing his observations of the innumerable nebulae, Herschel is led
presently to another curious speculative inference. He notes that some
star groups are much more thickly clustered than others, and he is
led to infer that such varied clustering tells of varying ages of the
different nebulae. He thinks that at first all space may have been
evenly sprinkled with the stars and that the grouping has resulted from
the action of gravitation.

"That the Milky Way is a most extensive stratum of stars of various
sizes admits no longer of lasting doubt," he declares, "and that our sun
is actually one of the heavenly bodies belonging to it is as evident. I
have now viewed and gauged this shining zone in almost every direction
and find it composed of stars whose number... constantly increases and
decreases in proportion to its apparent brightness to the naked eye.

"Let us suppose numberless stars of various sizes, scattered over an
indefinite portion of space in such a manner as to be almost equally
distributed throughout the whole. The laws of attraction which no doubt
extend to the remotest regions of the fixed stars will operate in such a
manner as most probably to produce the following effects:

"In the first case, since we have supposed the stars to be of various
sizes, it will happen that a star, being considerably larger than its
neighboring ones, will attract them more than they will be attracted by
others that are immediately around them; by which means they will be,
in time, as it were, condensed about a centre, or, in ot