Millheim Journal. [volume] (Millheim, Pa.) 1876-1984, 1882-10-12
Light and Heat.

The light, heat and other vibratory
emanations that are issued from the sun
are scattered around it in all directions
into space. II the sun were placed in the
centre of solid hollow shell that was
everywhere at the same distance as the
earth-that IS, approximately $4,000, 900
miles from the solar surface-all these
vibrations would impinge upon this outer
boundary wall. But as there Is no such
intercepting screen, they for the most part
pass still onward into space, and being
widely scattered there, are weakened by
the diffusion more and more, excepting
just where they fall upon the earth and
other planets chanclng TO he in the way.
1t appears, from consideration of the
distance and Size of the earth, that about
the two billion two hundred and fifty
millioneth part of the entire radiated
energy is thus caught by the earth, and
probably about ten times as much falls TO
the share of the other planets. This,
therefore, implies that scarcely more than
the two hundred and twenty-five mil
lioneth part of the radiant emery Is appro-
prlated by the planes, and that the rest is
Glssipated into space Nothing whatever
is yet known as TO what finally becomes
of the vast amount which thus wonders
off into the void fields of the measureless
immensely. What is done with the COM
parativelY small part that is intercepted
by the earth is clear enough. The solar
Vibrations that strike upon the earth rouse
its dead substance into life. They clothe
the terrestrial surface with its garment of
vegetation, feed its countless mynads Of
animated forms, work the mechanism of
its rivers and winds, warm the ground aud
air, and brighten the sunward half with
glowing light and glorious colors. That
is, at any rate, the result brought out from
the two billion two hundred and fifty
millionth part. 1t creates world teeming
with life out of dead. rocky chaos. Bat
nothing can be said as 10 what happens TO
the much larger part that trembles off into
the unbounded immensity. excepting that
TO all appearance it is lost to the sun and
in some way absorbed into the infinite void.
The common sense view of this subject
very naturally leads TO the idea that this
vast scattering OF light and heat from the
sun, which goes on SO increasingly, must
all be set down as less, at least 10 that
lumlnary. Vast and not as the solar
sphere is, il must in the end be chilled and
cease to emit these, to us so benetlcent
vibrations, unless there is some as yet un-
detected provision in nature for the re-
newal OF the solar rires. ALI our own ex-
perience Of such matters, derived from
the observation Of artificial processes GO
ling IN upon the earth, tell us that fires
,,lt thnxr ynaVinHi
cally supplied with fresh stores of fuel.
DR.. w. Siemens states in a recent con-
tribution 10 the Nineteeth Century, and no
doubt correctly states, that the present an
nual yield of all the coal mines Of the
earth would suffice 10 keep up the Are of
the sun, al its present intensity OF light
and beat, for the forty mlllionth part of a
second, that if the entire earth was made
of coal, il would serve as fuel supply for
feeding the solar fires about thirty SIX
hours. On the other hand. 1t has been
calculated that, even with no specific pro-
vision for restoring the waste radlatlons of
the sun, the mass is so vast and the heat
SO enormous that it could go on cooling by
free radiation into space for what, taken
IN reference TO mans method OF counting
the LAPSE OF time, would be a very long
period before any actual change of tenn
perature could be perceived. 1t Is toler-
ably sure that during the last 5000 or
1900 years of history, there has not been
any appreclsble dimlnution in the heat
communicated by the sun to the earth. 1t
Is tue that there have not been any trust
worthy records by thermometric instru-
ments for more than very small portion
of that time. But there are records, which
ere quite as significant, furnished by the
distribution OF vegetable life. Plants that
required the sustained warmth of genial
and approximately tropical climate, and
the same liberal allowance of solar In
huence that is now communicated TO the
earth, were quite rs widely distributed
upon the terrestrial surface, and quite as
vigorously maintained ages ago as they are
now, and the climate of Egypt was then,
as now, habitable by man