The new dominion. [volume] (Morgantown, W. Va.) 1876-1904, 1884-01-26

weight.
II is this tremendous power residing
in the suns mass which enables him to
guide the planets in their paths so that
they never retreat too far away from
him and so receive too little heat, nor
draw too close to him so as to receive
too much.
LIGHT AND HEAT.
But again, neither size nor power
would make the sun fit ruler of the
solar system, without light to illuminate
his family of worlds and heat to warm
them. Let ms see howsmuch light and
how much heat the sun gives out all the
time.
To get good idea of the suns light
we must remember his enormous extent
of surface. The earth's surface contains
two hundred millions of square miles;
the sun $ is eleven thousand six hundred
times greater Each square mile con-
tains about three millions of square
yards, each square yard about one thou
sand three hundred square inches;
whence it follows that there are roughly
eleven thousand six hundred times two
hundred million times three million
times one thousand three hundred
square inches in the suns surface, or in
round numbers 100000, 900, 900. 000,-
100000 square inches.
Now each of these gives out about six
hundred times as much light as the
glowing piece of lime in the oxhydro-
gen lantern used to obtain brilliantly
Illuminated magie-lantern pictures, and
more than one hundred times as much
light as the small but intensely brilliant.
electric arc when obtained of the utmost
possible splendor The whole surface
of the sun gives out instant by instant at
least as much light as million millions
of millions of millions of electric lights.
The heat given out by the sun is as
great as we might expect when we see
this enormous emission of light Ex.
periments made by Sir John Herschel
at one time and by Nj. Pouillet ut
another, show that the heat falling on
a single square mile only on the earth's
surface the sun being overhead l.
would melt twenty-six thousand tons of
ice in an hour.
Now the earth receives about fifty
million times as much heat as this, the
size of circle just large enough (set
squarely to the suns rays) TO shield the
earth from the sun being about fifty
millions of square miles. But the earth
only captures about one two-thousand-
millionth part of all the heat which the
sun emits. Thus the total heat given
out by the sun IN an hour would melt
two thousand six hundred millions of
millions OF millions of tons of ice in an
hour. This corresponds to what would
result from burning eleven thousand
eight hundred millions of millions of
tons of coal in a second
We can find Gas it chances) a ready
aid TO the memory--at least IL we re-
member, what has been already shown,
that the sun s surface is eleven thousand
eight hundred times larger than the
earth-by noting that ii our eartb's
surface were as hot as the suns she
would give out every second as much
heat as would come from burning a
billion Chat is amillion million) tons of
coal.
THE COMPOSITION OF THE SUN.
OF what is the sun, so vast and pow
erful, so hot and so brilliant, made? 1t
might seem hopeless to ask. Who
could traverse, even in Imagination,
the vast space that separates our world
from him and bring back news, across
the mighty gulf, Of the various sub
stances that form his glowing orb?
Yet science has done this, and that so
perfectly that we could scarcely be more
certain even if our observers had act
uallv visited the sun and had brought
back part of his substance for examina-
tor under the microscope or in chem
ical laboratories.
cannot here fully explain how this
has been done. But may say SO much
as this: The light of the sun contains
rays of all the colors Of the rainbow,
and method has been invented for sep
arating the red, orange, yellow, green,
blue, indigo and violet rays from each
other. When this is done it is found
that rays of certain tints are missing
from the light of the sun. Now, some
of these missing tints are known to be
those which certain vapors and gases
have the power of absorbing, as, for in
stance, the vapors of iron, zinc, cop
per and so forth, the gas hydrogen and
other substances in the vaporous or
gaseous form. We thus learn that these
substances are in the atmosphere of
the sun, much as the vapor of water and
the gases oxygen and nitrogen are
present in the atmosphere of the earth;
that is, in the air we breathe.
1t has thus been shown that hydro
gen, sodium, magnesium, calcium, iron,
aluminium, manganese, chromium, CO.
bait, nickel, zinc, copper, titanium and
other elements are present in the suns
atmosphere. In another way, by no.
ticing that certain tints are extra strong
in the suns light Gnstead of being alb
sent or faint) it has been shown that
oxygen is present (and probably also
nitrogen) in the atmos phere of the sun
as in our own.
SUN SPOTS.
The spots on the sun were first dis
covered by Fabricius, Calico and
Scheiner in the year 16l0. At first the
spots were thought to be opaque bodies
round the sun; but after |
awhile it was seen that they move in |
such way as to show that they are on |
his surface. Thus it was found that |
the sun turns round on his axis as the
earth does. The period in which he
thus turns on his axis is about twenty
five days, though as you will see pres
entity, we cannot be quite certain as to
the exact length of this period.
1t was presently discovered that the
spots appear only in certain parts of
the SUMS surface They are never seen
near his poles, nor near that circle
between the poles which cor
= Al