suggesting the notion of the little dog trotting
in front of his master, the man. The whole of
the upper left portion of the moon's disk is
uniformly sombre, but also less dark, in
general, than the decided spots that are seen to
the right. In that part, the unaided eye can
hardly make out any marked divisions; the
borders of the immense spot, which covers half
the western portion of the lunar disk, melt.
away and become confounded with the brighter
portions of our satellite. The northern extremity
of this great spot is formed by the Sea of
Rain; the southern end by the Sea of Clouds,
which is contiguous to the Sea of Humours.
Besides these spots, which occupy about a third
of the lunar disk, the unassisted eye can only
distinguish a confused sprinkling of luminous
points. Plutarch was the author of the notion
that the shaded parts of the moon are seas, from
which a fainter light would be reflected than
from areas of solid rock or land. He also
suspected that the spots might be extremely deep
caverns, which would entirely absorb the rays of
the sun.

On the map, or with a telescope of moderate
power, there is a marvellous change in the aspect
of the moon. The bright parts are covered with
apparently innumerable spots, like circular patches
of grease floating in a basin of mutton-broth, of
which nothing could be distinguished before, but
which, on closer inspection, appear as if bubbles
had burst on the surface of some molten metal,
which had suddenly cooled before the depression
made by the blister had time to till up again.
The moon's face is deeply pitted, scarred, and
seamed with a fiery small-pox, which must have
broken out in her early infancy, and which has
left indelible traces of its ravages. Some few
of these circular spots, which Galileo compared
to the eyes on a peacock's tail, are surrounded
by straight rays, which radiate from them as if
from a central luminous star. Not far from the
south pole, in the midst of the great luminous
patch which nearly covers the southern
hemisphere, is the remarkable circular mountain,
Tycho, from which a number of slightly curved
rays stretch to a great extent in all directions,
giving to that part of the moon somewhat the
appearance of being slightly ribbed like a melon.
Most extraordinary phenomena also are sundry
bright, wavy, narrow stripes, some single and
some branched, one of which crosses the Sea of
Serenity; another runs along one side of the
Sea of Crises; another lies on the north-western
edge of the moon, beyond the Ocean of Tempests.
One of the darkest spots on the moon, the inner
part or crater of a circular mountain, named
Plato, is not far from the north pole, a little to
the west of the central meridian. It looks as
black and hollow as if it were an immense dry
well of a profundity that baffles imagination. It
is a bottomless peak cavern, but with no stream
of water gushing out of its yawning, thirsty
mouth. The small craters in the moon are
countless; more than fifty thousand have
been already observed. No attempt has been
made to delineate them in Lecouturier's map,
whose aim has been clearness rather than
profuse detail.

Of all the heavenly bodies, the moon is the
nearest to us and the easiest to observe. It is
especially interesting as the boundary between:
astronomy and meteorology; everything above
the moon is in the celestial heavens, and
consequently belongs to the former science;
everything below the moon is in the terrestrial sky,
in the atmosphere, and therefore lies within the
domain of the latter. The connexion between
the moon and the earth is closer than is often
suspected. If a line be drawn from the centre
of the earth to the centre of the moon, there
lies in it a point (much nearer to the moon than
to us) where the moon's and the earth's attraction
on any material object are exactly equal. If
the object be removed a little-towards us, it will
fall upon the earth; a little the other way, it
will be drawn towards the moon. Arago has
calculated the force necessary to shoot a body
from, the moon to reach this intermediate point
of equilibrium, and finds it to be by no means
an impossible or unattainable force.
Consequently, it is not improbable that many (though
perhaps not all) of the meteoric stones that
fall, are sent hither from the moon. It would
be very possible for an inhabitant of the moon,
supposing such inhabitant to exist, to keep up a
daily communication with the earth by means of
projectiles. For us to reply to the correspondence,
would be immensely more difficult. The
nearness and conspicuousness of the moon have
caused the human race, from the highest
antiquity, to attribute to it great influence on the
variations of the weather.

The earth and the moon are planets, or
wandering globes, both receiving their light from
their common centre of attraction, the sun; but
the moon is much the greater wanderer of the
two; for, being a satellite, or follower, she is
constantly travelling round her principal, while
her principal only travels round the sun. Her
orbit round the earth not being circular but
elliptical, she is sometimes nearer to us than
at other times, the extreme difference of distance
being about twenty-five thousand miles. Her
mean distance from the earth is about two
hundred and forty thousand miles, which is a mere
trifle compared with the distances of the other
planets, and which looks like proximity itself if
we consider the distances even of the nearest
fixed stars. The moon is about two thousand
one hundred and seventy-five miles through. ln
regard to volume, or size, she is only one forty-
ninth of the magnitude of the earth; to compare
their respective densities or heaviness, the earth,
taken as a whole, is nearly five and a half times
as heavy as water, while the moon is only
something more than three and a quarter times as
heavy as water. If we weigh one against the
other, we must put eighty-eight globes like the
moon into one scale before it will balance the
earth in the other.

The most remarkable fact is that the moon
always shows us one and the same illuminated
face; which is said to be caused by the perfect