BY DAY AND BY NIGHT.
Let us take a good look up into the sky, and see what is to be found
there.
First, by day. Beginning in the early morning, just before sunrise,
we have perhaps a clear sky, grayish rather than blue, and towards
the east a brightening glow shows that the Sun is about to appear.
That glow grows stronger and stronger, and soon a tiny glimmer creeps
up over the rounded surface of our earth. Then the broad golden face
follows, till the sun is visible, and full daylight has arrived.
But the Sun does not stand still there, low down on the horizon. He
goes on rising higher and higher, “climbing the heavens” steadily, one
hour after another. At mid-day--twelve o’clock--he has reached his very
highest point. Then he begins to descend, moving downward towards the
west till he reaches the western horizon and vanishes from our sight.
The Sun always rises in the East; never in the West. He always sets in
the West; never in the East.
By this I mean that he always rises to _the_ _east of our world_ and
sets to _the west of our world_. He rises on the eastern side of the
Earth and sets on the western side. You must not suppose that he always
rises due east and sets due west of all countries in the world at once.
On two days only he does so--that is at the Spring Equinox, on March
21st, and at the Autumn Equinox, on Sept. 21st. “Equinox” means “Equal
Nights.” At those two dates days and nights are of the same length,
twelve hours each, throughout the whole world; and everywhere the Sun
rises exactly in the east, and sets exactly in the west.
Everywhere except at the north and south poles. There the Sun is seen
to circle round the sky in twenty-four hours, just above the horizon,
neither rising nor setting.
A man standing on the equator at one of the equinoxes sees the Sun rise
just in the east; climb high in the sky just over his head; and set
just in the west.
People living in the northern parts of Europe and of America do not see
precisely the same thing. With them the Sun does not circle round the
sky, just over the horizon, as at the poles. And though he rises in the
east and sets in the west, as at the equator, he does not reach the
highest point in the sky, but only a point somewhat lower down, towards
the south.
The very highest point in the sky, exactly over one’s head, is called
“the zenith.” In northern countries the Sun never gets to the zenith.
No; not even on the very hottest summer day. He is always towards the
south.
There are two other dates, which you ought to learn, besides the
_Spring Equinox_ and the _Autumn Equinox_. These are--the _Summer
Solstice_, on June 21; and the _Winter Solstice_, on December 21.
On the 21st of June the Sun is not exactly overhead at the Equator, as
at the Equinoxes. He has come farther north; not nearly so far north as
England or Canada, but as far north as he ever does come.
By that time days and nights are not at all equal through the world.
In the north of Europe and America we have long days and short nights;
while our friends in Australia have long nights and short days.
Although the Sun is never actually overhead with people in the northern
parts of Europe and America, but is always somewhat to the south, even
at his highest point, still he climbs very much higher in June than in
March or September, and so he is much longer above the horizon.
Things are quite the other way on the 21st of December. Then the Sun is
overhead, not farther north than the Equator, but farther south. Then
it is summer in the southern hemisphere and winter in the northern.
Then we who live in England or in the northern parts of North America
have long nights and short days, while our friends in Australia are
having long days and short nights.
Then, too, in the north, the highest point at mid-day which the Sun can
reach is low down in the south; and his rays come to us in a slanting
manner, with far less power to warm than when they are poured down from
nearly overhead. That is why we are so cold in the dark months of the
year.
At the equinoxes the Sun rises to the east and sets to the west of
almost the whole Earth.
In our northern summer the Sun rises to the north-east, travels round
by the south, and sets in the north-west.
In our northern winter, the Sun rises to the south-east, climbs up a
little way, and sets in the south-west.
These changes come about slowly. Every twenty-four hours there is a
difference. Each day of spring the Sun rises and sets a little more to
the north, and climbs higher in the sky. Each day of autumn he rises
and sets a little more to the south, and climbs less high in the sky.
But all the while, though he may rise to the north-east or south-east
of New York or London or some other particular spot, he rises to the
east of the _world_; though he may set to the north-west or south-west
of any particular spot, he sets to the west of the _world_.
You will find a grand description in the 19th Psalm of this daily
journey of “the Sun, which is as a bridegroom coming out of his
chamber, and rejoiceth as a strong man to run a race. His going forth
is from the end of heaven, and his circuit unto the ends of it; and
there is nothing hid from the heat thereof.”
The full meaning of that heat and strength can hardly be known in
northern lands. Their hottest summer day’s heat is as nothing, compared
with the scorching blaze and glare of the Sun in countries nearer to
the equator--for instance, in that country where the Psalm was written.
Through all the ages of our world’s history, from the very beginning,
the radiant Sun has risen and set, day after day. Morning after morning
he has come up from beyond the horizon on one side; evening after
evening he has vanished below the horizon on the other side. Year after
year, and century after century, still “like a strong man” he runs his
daily race, and warms and lights each side of the world in turn.
Now about the Sky at night. What happens when the Sun is gone?
The bright blue of the sky grows fainter and more dull, and stars begin
to show themselves.
First, one little twinkle is seen; then another little twinkle; then
a third; till, if it be a clear evening, the whole sky is dotted with
gleaming points. Some are more bright, some are less bright. Here one
flashes like a diamond, with different colors; there another is so dim
as hardly to be seen at all.
It may be that we have caught sight of the Moon before the Sun has
set--should she happen to be in a right place in the sky, not too near
to the Sun. While he is up, if we get a glimpse of her at all, she
looks like a mere pale patch of whiteness. But when the Sun is gone,
and darkness deepens, she changes fast; and soon she is lighted up with
a soft silvery glow, sending her beams to the Earth.
Now, you all know--everybody knows--that the Sun rises each morning,
crosses the sky, and sets each evening.
But perhaps not every boy and girl knows quite so clearly that the Moon
and the Stars behave very much in the same manner. They too, either in
the day or in the night, rise and cross the sky and set; and at night
we may see them do it.
We cannot always watch the rising and setting of the Moon: for when
she rises in the day-time her soft beams are often lost in the glare
of sunlight. Still she is always there, in the sky: always rising and
setting to _some_ part of our Earth. When we say, as we often do, “Is
there a moon to-night?” we mean, “Is the moon where we can see her
to-night?” There is always a Moon, and there is always the same Moon.
As to the Stars, their movements are puzzling, no doubt. No two stars
rise at the same point or take just the same path over the sky, or set
on the same spot. Some rise exactly east, and set exactly west. Some
rise in the south-east and set in the south-west. Some rise in the
north-east, and set in the north-west.
No star is ever seen, however, to rise anywhere towards the _west_, and
to travel backwards towards the _east_. All the stars in company move
as a whole _from the eastern side of the world towards the western side
of the world_. That is to say, they seem to move thus.
Some stars to the north do not rise or set at all, as seen from the
northern parts of Europe and North America. They only travel round and
round, in a circle about the Pole-star, which is almost exactly over
our north pole. Yet their movements too are from east to west.
If we lived in the southern hemisphere we should see the same thing
going on nightly, only with a different set of stars.
Then the far-south stars would circle round and round over the south
pole; and those lying over the north pole would be hidden by the Earth
lying between. But still the whole movement would be always from east
to west; never from west to east.
Each tiny star, bright or dim, takes its daily journey, like the sun,
once in twenty-four hours. No matter whether it has to go right round
the whole Earth or whether it only has to creep in a small circle round
the Pole-star--still the journey is always the same in length: always
close upon twenty-four hours. At the end of twenty-four hours it is
back at its starting point, and begins over again. Just as the Sun does.
If you look out at night sometimes, and watch carefully, you will see
for yourself something of this constant nightly journeying of the stars.
QUESTIONS.
1. Where does the Sun rise and set?
The Sun rises in the East and sets in the West.
2. Always in the East and West exactly?
Always to the east of our world and to the west of our world. Not due
east and due west of each particular country always.
3. When is the Spring Equinox?
On the twenty-first of March.
4. When is the Autumn Equinox?
On the twenty-first of September.
5. What does the word Equinox mean?
Equal nights. At the Equinox, days and nights are of the same length
over almost the whole world.
6. When is the Summer Solstice?
On the twenty-first of June.
7. When is the Winter Solstice?
On the twenty-first of December.
8. In what direction does the Sun rise and set at the Equinoxes?
At each of the equinoxes the sun rises due east, and sets due west,
over all the world, except at the poles.
9. At the Summer Solstice where does the Sun rise and set?
To people in England, or in Canada, or in the northern States, he rises
in the north-east and sets in the north-west.
10. And in the Winter Solstice?
To those same places he rises then in the south-east and sets in the
south-west.
11. What do we call the highest point in the heavens, exactly over
one’s head?
The zenith.
12. Does the Sun ever reach the zenith in England, or in the northern
parts of North America?
Never. He rises much higher in summer than in winter at midday, but he
is always to the south of the highest point.
13. When or where may the Sun be seen precisely overhead?
On the equator, at the two equinoxes.
14. At what hour of the day may the Sun be seen exactly overhead?
Only at Mid-day.
15. Do any other heavenly bodies rise and set?
Yes; the Moon and the Stars; in fact, nearly all the heavenly bodies.
16. Can we see the Moon rise and set?
Sometimes; not always.
17. Tell me one reason why we sometimes do not see the Moon.
Sometimes she rises and gets at about the same time as the Sun; and
then she is hidden by his brightness.
18. How do the Stars rise and set?
Like the Sun and Moon, they rise in the east of the world and set in
the west of the world.
19. Do all the Stars take the same journey?
Some rise due east, some north-east, some south-east; and they set
either due west, or north-west, or south-west.
20. Does every Star that we can see rise and set?
No; many stars to the far north never rise nor set to us in England or
the northern States, but circle round and round the pole-star.
21. How long a time does this journey take--either round the world or
round the pole-star?
Nearly twenty-four hours for each star.