ended in the overthrow of
the rebel angels, Milton, in his description of their armour, says:--

two broad suns their shields
Blazed opposite.--vi. 305-306,

and in describing the faded splendour of the ruined Archangel, the poet
compares him to the Sun when seen under conditions which temporarily
deprive him of his dazzling brilliancy and glory:--

as when the Sun new-risen
Looks through the horizontal misty air
Shorn of his beams, or, from behind the Moon
In dim eclipse, disastrous twilight sheds
On half the nations, and with fear of change
Perplexes monarchs.--i. 594-99.

This passage affords us an example of the sublimity of Milton's
imagination and of his skill in adapting the grandest phenomena in
Nature to the illustration of his subject.

THE MOON

The Moon is the Earth's satellite, and next to the Sun is the most
important of the celestial orbs so far as its relations with our globe
are concerned. Besides affording us light by night, the Moon is the
principal cause of the ebb and flow of the tide--a phenomenon of much
importance to navigators. The Moon is almost a perfect sphere, and is
2,160 miles in diameter. The form of its orbit is that of an ellipse
with the Earth in the lower focus. It revolves round its primary in 27
days 7 hours, at a mean distance of 237,000 miles, and with a velocity
of 2,273 miles an hour. Its equatorial velocity of rotation is 10 miles
an hour. The density of the Moon is 3.57 that of water, or 0.63 that of
the Earth; eighty globes, each of the weight of the Moon, would be
required to counterbalance the weight of the Earth, and fifty globes of
a similar size to equal it in dimensions. The orb rotates on its axis in
the same period of time in which it accomplishes a revolution of its
orbit; consequently the same illumined surface of the Moon is always
directed towards the Earth. To the naked eye the Moon appears as large
as the Sun, and it very rapidly changes its form and position in the
sky. Its motions, which are of a very complex character, have been for
many ages the subject of investigation by mathematicians and
astronomers, but their difficulties may now be regarded as having been
finally overcome.

The phases of the Moon are always interesting and very beautiful. The
orb is first seen in the west, after sunset, as a delicate slender
crescent of pale light; each night it increases in size, whilst it