The sun is bright, and the earth is dark. The sun gives light and heat,
and the earth receives light and heat. We should be in utter darkness
were it not for the sun; at least, all the light we should have, beyond
our trivial artificial light, would come from the feeble twinkle of
the stars. The moon would be no use, for the brightness of the moon is
merely the reflection of the sunbeams. Were the sun’s light completely
extinguished we could never again see the moon, and we should also miss
from the sky a few other bodies, which we call planets, such as Jupiter
and Venus, Mars and Saturn. But the stars would be the same as before,
for they do not depend upon the sun for their light. We shall, indeed,
afterwards see that each star is itself a sun.
Picture to yourself the earth as receiving a stream of sunbeams. These
beams fall on one half of our globe, and give to it the brilliance
of day. The other half of the earth of course receives no sunlight.
It is in the shadow, and consequently the darkness of night there
prevails. The boundary between light and darkness is not quite sharply
defined, for the pleasant twilight softens it a little, so that we
pass gradually from day to night. Looking at the progress of the sun
in the course of the day, we see that he rises far away in the east,
then he gradually moves across the heavens past the south, and in the
evening declines to the west, sets, and disappears. All through the
night the sun is gradually moving round the opposite side of the earth,
illuminating New Zealand and Japan and other remote countries, and then
gradually working round to the east, where he starts afresh to give us
a new day here.
Our ancestors many ages ago did not know that the earth was round. They
thought it was a great flat plain, and that it extended endlessly in
every direction. They were, however, much puzzled about the sun. They
could see from the coasts of France and Spain or Britain that the sun
gradually disappeared in the ocean; they thought that it actually took
a plunge into the sea. This would certainly quench the glowing sun;
and some of the ancients used to think they heard the dreadful hissing
noise when the great red-hot body dropped into the Atlantic. But there
was here a difficulty. If the sun were to be chilled down every evening
by dropping into the water hundreds of miles away to the west, how did
it happen that early the next morning he came up as fresh and as hot as
ever, hundreds of miles away to the east? For this, indeed, it seemed
hard to account. Some said that we had an entirely new sun every day.
The gods started the sun far off in the east, and after having run
its course it perished in the west. All the night the gods were busy
preparing a new sun to be used on the succeeding day. But this was
thought to be such a waste of good suns that a more economical theory
was afterwards proposed. The ancients believed that the continents of
the earth, so far as they knew them, were surrounded by a limitless
ocean. At the north, there were high mountains and ice and snow, which
they thought prevented access to this ocean from civilized regions.
Vulcan was the presiding deity who navigated those wastes of waters,
and to him was intrusted the responsible duty of saving the sun from
extinction. He had a great boat ready, so that when the sun was just
dropping into the ocean at sunset he caught it, and during all the
night he paddled with his glorious cargo round by the north. The glow
of the sun during the voyage could even be sometimes traced in summer
over the great highlands to the north. This, at all events, was their
way of accounting for the long midsummer twilight. After a tedious
night’s voyage Vulcan got round to the east in good time for sunrise.
Then he shot the sun up with such terrific force that it would go
across the whole sky, and then the industrious deity paddled back with
all his might by the way he had come, so as to be ready to catch the
sun in the evening and thus repeat his never-ending task.