pses are Predicted--Uses of the Moon in finding
Longitude--The Moon not connected with the Weather--Topography of
the Moon--Nasmyth's Drawing of Triesnecker--Volcanoes on the
Moon--Normal Lunar Crater--Plato--The Shadows of Lunar
Mountains--The Micrometer--Lunar Heights--Former Activity on the
Moon--Nasmyth's View of the Formation of Craters--Gravitation on
the Moon--Varied Sizes of the Lunar Craters--Other Features of the
Moon--Is there Life on the Moon?--Absence of Water and of Air--Dr.
Stoney's Theory--Explanation of the Rugged Character of Lunar
Scenery--Possibility of Life on Distant Bodies in Space.

If the moon were suddenly struck out of existence, we should be
immediately apprised of the fact by a wail from every seaport in the
kingdom. From London and from Liverpool we should hear the same
story--the rise and fall of the tide had almost ceased. The ships in
dock could not get out; the ships outside could not get in; and the
maritime commerce of the world would be thrown into dire confusion.

The moon is the principal agent in causing the daily ebb and flow of the
tide, and this is the most important work which our satellite has to do.
The fleets of fishing boats around the coasts time their daily movements
by the tide, and are largely indebted to the moon for bringing them in
and out of harbour. Experienced sailors assure us that the tides are of
the utmost service to navigation. The question as to how the moon causes
the tides is postponed to a future chapter, in which we shall also
sketch the marvellous part which the tides seem to have played in the
early history of our earth.

Who is there that has not watched, with admiration, the beautiful series
of changes through which the moon passes every month? We first see her
as an exquisite crescent of pale light in the western sky after sunset.
If the night is fine, the rest of the moon is visible inside the
crescent, being faintly illumined by light reflected from our own earth.
Night after night she moves further and further to the east, until she
becomes full, and rises about the same time that the sun sets. From the
time of the full the disc of light begins to diminish until the last
quarter is reached. Then it is that the moon is seen high in the heavens
in the morning. As the days pass by, the crescent shape is again
assumed. The crescent wanes thinner and thinner as the satellite draws
closer to the sun. Fina