which is not surprising, seeing that the eye is so restricted,
and the object so remote.

Dr. Dick, whose productions have done much to popularize the
study of the heavens, and to promote its reverent pursuit, says: "On
the whole it appears most probable that the moon is surrounded with
a fluid which serves the purpose of an atmosphere; although this
atmosphere, as to its nature, composition, and refractive power, may
be very different from the atmosphere which surrounds the earth. It
forms no proof that the moon, or any of the planets, is destitute of
an atmosphere, because its constitution, its density, and its power of
refracting the rays of light are different from ours. An atmosphere
may surround a planetary body, and yet its parts be so fine and
transparent that the rays of light, from a star or any other body, may
pass through it without being in the least obscured, or changing their
direction. In our reasonings on this subject, we too frequently
proceed on the false principle, that everything connected with other
worlds must bear a resemblance to those on the earth." [447] Mr.
Neison, who has written one of the latest contributions to the
science of selenography, says, "Of the present non-existence of
masses of water upon the surface of the moon, there remains no
doubt, though no evidence of its entire absence from the lunar crust
can be adduced; and similarly, many well-established facts in
reference to the moon afford ample proof of the non-existence of a
lunar atmosphere, having a density equal to, or even much less than,
that of the earth; but of the absence of an atmosphere, whose mass
should enable it to play an important part in the moulding of the
surface of the moon, and comparable almost to that of the terrestrial
atmosphere, in their respective ratios to the masses of their planets,
little, if any, trustworthy evidence exists." On another page of the
same work, the author affirms "that later inquiries have shown that
the moon may possess an atmosphere that must be regarded as fully
capable of sustaining various forms of vegetation of even an
advanced type; and, moreover, it does not appear how it can justly
be questioned that the lunar surface in favourable positions may yet
retain a sufficiency of moisture to support vegetation of many kinds;
whilst in a very considerable portion of the entire surface of the
moon, the temperature would not vary sufficiently to materially
affect the existence of veg