Evening star. [volume] (Washington, D.C.) 1854-1972, 1892-05-20

q Body rAaa - Tee lsseasely Hot -

Il
a Body TAss - Tee lsssaseiy Hot -
4 nlnss.
Prof c. 4 Youns. sn cssrsso Tr1suns.
| Sunlight 10 many times brighter than ~
artificial light. Hence has arisen . rather com
mon idea that there 10 something mysserioas
about It, that sunshine cannot be explained 10
the same way - the light Of fame, fos In
stance.
The sun shines simply becauss Il b hot-trs-
mendoukly %. The sun does not shine o. fro
hies and glow worms do; they give light only,
without much beat, emitting only rays thas
Affect the eyes.
The sun sends Oh rays Of all kinds-not only
BILE aud yet are powerful In their action upon
Photographic plate, and still others which are
squaiiy invisible, but bring an immense amonnt
| Of warmth TO the earth.
The visible rays of the sun-its light, in the
strict sense Of the word lght--form but q small
Traction OF tts whole radiation Now, only very
hot bodies act In this way. "Phosphorcsceut"
bodies. which emit visible rays alone without
| Others In their company, may be cool while they
shine; not 30 those which send out all kinds Of
rays together.
| That the sun Is really nost intensely hot 10
directly shown by means of burning glass.
Many years ago a great lens OF this sort,
l sse@av Aooh iSCt uCtOhs. was maQe In En&iAH0
| - present 70 the Emperor Of China. Before
1t was cent on some experiments were made
| with II, and the results were very interesting
and instructive. When properly set up in
bright sunshine and adjusted il gathered all the
rays that fell upon its broad surface into small
bright spot called the focus" (the word means
Fireplace }, and there the concentrated heat
| was 80 intepse that nothing could be found Ia
| withstand Il. The focus was hotter than the
intensest hsme we know how to make. 40 that
even lime and platinum melted in II like wax.
Now, The point Is that such focus can never
be quite SO hot q the surface of the cum itself.
In this case it was only about a. hot as Il would
| be at q distance from the sun equal 10 the
moons distance from the earth.
| There Is no question that the suns surface Is
intensely hot; and 10 it must shine Of
hot2"
Until the days Of electricity nearly all our
artificial lights came from Aames in which some
thing was burning; h the suns surface, then, q
burning fame?
| No. II is too hot TO burn.
The very essence OF combustion or burning
u that two or more chemical elements are en-
tering into combination sith each other. pro-
ducing heat in the process. When stick OF
WOOD burns the oxygen OF the air is selling
upon and combining with the hydrogen and
carbon that mainly compose the wood: and
| the molecules Of carbon, after their hydrogen
partners have combined with oxygen compan-
| ions. Themselves are attracted by other oxygen
molecules, and glow and shine for while until
| consumed and converted by the new union
into the so-called carbonic acid. Now, this
combination Of oxygen and carbon produces a
| certain fixed temperature, which can never be
exceeded by fame involving those materials
and IL the molecules Of oxygen and hydrogen
or il oxygen and carbon come together at a
higher temperature. !. g., in some place where
it Is already hotter than they could make il by
their union, they refuse TO combine. Nay,
| further. vapor OF wAter or carbolic acid gas
be exposed to such . temperature their oom-
post molecules come to pieces, SO TO spesk-to
use the technical term the hydrogen and oxy-
gen or the carbon and oxygen are ''disso-
ciatsd"-to combine again as soon as the tenn.
persture falls sufficiently.
Now, the suns surface is in all probability
hotter than the "dissocistion" temperature OF
any elements known to be present there and
stances Of the sun are "too hot TO burn"
But there are other ways than burning by
which heat may be generated and the temper
sture raised beyond any limit known.
A smith, by hammering nail, with proper
precautions, can make il red hot. In boring q
heated. Sometimes car axles are heated by
friction till they set the car on fire. In CON-
| pressing air for certain machinery Il lie made
intensely hot. 40 that means have to be used 10
prevent II doing damage
Now, 1t is believed that the sun Is great ball
in size.
There b no question that the shrinkage OF
| such o ball under the force of the mutual at
traction Of it, particles must heat it, 1t can be
proved mathenatically-it is not mere matter
| OF guesswork or opinion--that If the sun is now
shrinking at such rate that its diameter dimin-
ishes more than about 800 feet g wear il must be
| growing continually hotter. II the shrinkage is
less than tins 1t may be cooling OF slowly.
| Almost al astronomers agree in supposing
that at one time, ages ago, the sun was q great
whirling nebuls or cloud, filing the whole space
now occupied by the sols- system, and that the
system has come into its present condition by
the slow condensation Of this primeval cloud
| The smaller globes-the planets-have solidified
and ceased to shrink to any great extent, and 90
have cooled down more or less completely, like
| the earth. But in the great central globe the
process Is not finished, and ID not likely TO be
for millions Of years 10 come. so il still glows
| with fiery heat that no furnace can rival and
blazes with briliance more dazzling than any
human art can produce.
| For myself do not think it necessary to look
further for an explanation Of the intensity Of
sunlight.
But there are some who do not feel quite sat-
ished and are disposed to call In the aid Of
| electrical action.
tits true, OF course, that thing can be heated,
| and that to . temperature beyond any known
limit, by passing through i. an electric current
Of sufficient intensity. The carbon filament in
an electric (incandescentl lamp is not burn
| ing" but Is made hot and luminous by the cur
| rent flowing through it.
Those, therefore, who are dissatisfied with
the mechanical explanation of the solar heat as
produced by shrinkaGe maintain that the suns
light IL generated by intense electric currents
circulating upon its surface.
II would take too long to show why this IL
hardly likely and the discussion would not be
| suited to these columns; but there is no wHy
| known In which electric currents of sufficient
power could be made 10 act over the whole
| surface Of Q sphere at once, nor any reason to
suppose that Il can be done. Still, il Is quite
possible, and even likely, that the exceptional
brilliance Of small portions of the surface here
and there may be caused in part by some action
Of the sort, adding intensity 10 the light due to
the general heat Of the luminous shell.
Editors Junketing In California.
10 Cd n