The Meeker herald., 1915-07-24
HEAT OF our sun
To Measure 1t Is a PerpIexing
Problem Fer Science.
NEWTON ONCE TRIED TO DO 1T
He Figured It at the Amazing Intensity
Of 1866. 800 Degrees centisrade, While
the Latest Estimates Place It at
About $500 Degrees.

the Latest Estimates Place II at
About $500 Degrees.
How hot Is the sun? The question
has been answered in many different
ways. and it is by no means certain
that we have yet arrived ut an even
approximately accurate answer. Yet
1t would seem that, as the sun is tue
only source of the clrtlI's heat and
as we know the exact distance of the
sun, II ought to he easy To calculate
his heat. That is what Newton thought
In 1850 when. finding that II tliermom
eter registered 10 degrees q. in the
sun and 29.H degrees e. in the shade.
and applying the law of the square of
distance he announced that the suns
heat was l.660. 300 degrees c.!
In 1887 Sir John Herschei and Pouil-
let devised special Instruments Tor
measuring the solar heat but ut the
very beginning disagreed on funda
mental question. Pouillet wanted to
estimate that the earth's atmosphere
cut of half the suns heat: Herschei
insisted that 1t cut OF only onc'third.
Herschel reached the conclusion that
the suns heat was two calorieS per
square centimeter per minute Pouil-
let calculated 1t ut 1.iG;'3 caluries per
square centimeter per minute This
means that the suns rays falling YER
tically upon each square centimeter of
the earth's surface would he sufficient
ly powerful. If it We're not for their
absorption by our atmosphere. to raise
1.7G33 grams of water one degree g.
per minute This number is what as
tronomers Gull the solar constant
Pouillcts figures. IL. Were generally
accepted until recently. Forbes by eS
periments at the top and ut the base
of high mountain calculated that 2.Sb
was the correct number. Wolfe made
1t 2.54. and Crova asserted that it was
certainly superior to two calorics per
square centimeter per minute.
The American Langley invented the
bOlometer. by means of which he
measured the intensity of each ray by
the length of its wave before entering
our atmosphere. Thus he proved that
the rays Of shortest length are those
that are most absorbed 1t is us If we
placed two red glasses between our
selves and the sun. one representing
the suns atmosphere and one repre-
senting our own
The Able MOreux, director OF the
Bourges observatory. declares in an
article In Cosmos that II these two at
mOspheres were eliminated and we
could see the sun as he really is he
would appear to he brilliant grcenish
blue.
Langley's calculations placed the
La constant ut about three. He proved
that scarcely GO per cent of the suns
rays penetrated to sea level.
Other observers obtained other fig
ures, and at the beginning of this cen
fury the tendency was to return TO
those announced by Herschrl ana
POuillet.
1t Is certain that the earth intercepts
only about one two-billionth part of
the actual heat of the sun. but If we
adopt Langley's figure. ). we find that
the fraction of heat received would be
sufficient to melt annually n layer of
ice 22222.75 feet thick Mt the equator of
the earth. The average power receiv-
is equal to 1J4.4G4.0OO kilogrammeters
year. or one continuous horsepower
for every liz square meters.
The greater part of this heat is used
up In keeping the earth warm; but. ac-
cording to Helmholtz. about thou
sandth part of it is absorbed by ami
mails and vegetables and becomes an
abundant reserve of energy for the
human race.
II We accept the more recent figures.
which are the result Of the calculations
Of Messrs. Abbott. Fowle and Aldrich
at the Smithsonian institution in
Washington and call the solar constant
two calories per square centimeter per
minute. the results are scarcely less
striking.
If the total heat could be applied to
block OF ice at o degrees c. us thick
Ms the earth-SO00 miles-this would
be entirely melted in a quarter of an
hour. All the water thus obtained
would be turned to steam ut 100 de-
grees c. III minutes later. the whole
operati ton from ice to steam having
taken only. two hours and twelve min
utes.
The most recent estimate OF the TEN
perature OF the suns surface is be
tween G.OOO and 1000 degrees C.-New
York World.
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