St. Tammany farmer. [volume] (Covington, La.) 1874-current, 1884-02-09

non TWO hundred and sixty thousand
times larger than the earth: but he only
contains aboutthree hundred and thirty
thousand times as much matter. Still
even this Is enormous, and means enor.
nous power. If the earth had such
power, the quantity of matterin pound
would press downwards with rs much
force rs three hundred and thirty thou.
sand pounds weight at present. Amar
H'ho weighs only one hundred pounds
would in that case weigh thirty-three
millions of pounds. or would in fact
be crushed perfectly fiat by his own
weight.
1t 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 a fit ruler of the
solar system, without light to illuminate
his family of worlds and heat to warm
them. Let us see how much 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 S 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 sun s surface, or in
round numbers 5000, 900, 900, 900, 900 :
OOO,OO0 square inches.
Now each of these gives out about six
hundred times as much light rs the
glowing piece of lime in the oxhydro-
gen lantern used to obtain brilliantly
Illuminated magic-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 at
another, show that the heat falling on
. single square mile only on the earth's
sun being overhead
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 a circle just large enough (set
squarely to the suns ravs) to shield the
earth from the sun being about fifty
of square miles. But the earth
only captures about one 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 second
We can find Gas it chances) a ready
aid to the memory-at least if we re
what has beD already shown.
hat the sun S surface is eleven thousand
eight hundred times larger than the
earth-by noting that ii our earth's
surface were as hot as the suns she
would give out every second as much
heat as would come from burning a
billion (that is amillion million) tons of |
,oal.
THE COMPOSITION OF THE sun.
Of what is the sun, so vast and pow
,rful, so hot and so brilliant, made? 1t |
night seem hopeless to ask. Who
'Ould traverse. even in imagination,
he vast space that separates our world
rom him and bring back news, across
he mighty gulf, of the various SUBJ
tances that form his glowing orb2
let science has done this, and that so
that we could scarcely be more
allv visited the sun and had brought
ack part of his substance for examina-
ion under the microscope or in chem
cal Laboratories.
/ cannot here fully explain how this
as been done. But may say SO much
S this: The light of the sun contains
avs of all the colors of the rainbow,
nd method has been invented for sep
rating the red, orange, yellow, green,
lue, indigo and violet rays from each
ther. When this is done it is found
nat rays of certain tints are missing
-om the light of the sun. Now, some
these missing tints are known to be
nose which certain yapors and gases
ave the power of absorbing, as, for in
lance, the vapors of iron, zinc, cop
er and so forth, the gas hydrogen and
Their substances in the vaporous or
aseous form. We thus learn that these
distances are in the atmosphere of
he sun, much as the vapor of water and
le gases oxygen and nitrogen are
resent in the atmosphere of the earth;
lat is, in the air we breathe.
1t has thus been shown that HYDRO
en-, sodium, magnesium, calcium, iron.
uminium, manganese, chromium, CO.
alt, nickel. zinc, copper, titanium and
her elements are present in the suns
In another way. by no ,
cling that certain tints are extra strong .
the suns light Gnstead of being alb
mt or faint) it has been shown that
sygen is present (and probably also
trogen) in the atmosphere of the sun
, in our own.
SUN SPOTS. 8