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Page 11
Thus we have brought to our doors a readable record of the very
substances composing every world hot enough to shine by its own
light. Thus, while our flag means all we have of liberty, free as
the winds that kiss it, and bright as the stars that shine in it,
the flag of the sun means all that it is in constituent elements,
all that it is in condition.
We find in our sun many substances known to exist in the earth,
and some that we had not discovered when the sun wrote their names,
or rather made their mark, in the spectrum. Thus, also, we find
that Betelguese and Algol are without any perceivable indications
of hydrogen, and Sirius has it in abundance. What a sense of
acquaintanceship it gives us to look up and recognize [Page 30] the
stars whose very substance we know! If we were transported thither,
or beyond, we should not be altogether strangers in an unknown
realm.
But the stars differ in their constituent elements; every ray that
flashes from them bears in its very being proofs of what they are.
Hence the eye of Omniscience, seeing a ray of light anywhere in
the universe, though gone from its source a thousand years, would
be able to tell from what orb it originally came.
_Creative Force of Light._
Just above the color vibrations of the unbraided sunbeam, above
the violet, which is the highest number our eyes can detect, is
a chemical force; it works the changes on the glass plate in
photography; it transfigures the dark, cold soil into woody fibre,
green leaf, downy rose petals, luscious fruit, and far pervasive
odor; it flushes the wide acres of the prairie with grass and flowers,
fills the valleys with trees, and covers the hills with corn, a
single blade of which all the power of man could not make.
This power is also fit and able to survive. The engineer Stephenson
once asked Dr. Buckland, "What is the power that drives that train?"
pointing to one thundering by. "Well, I suppose it is one of your
big engines." "But what drives the engine?" "Oh, very likely a canny
Newcastle driver." "No, sir," said the engineer, "it is sunshine."
The doctor was too dull to take it in. Let us see if we can trace
such an evident effect to that distant cause. Ages ago the warm
sunshine, falling on the scarcely lifted hills of Pennsylvania,
caused the reedy vegetation to grow along the banks of [Page 31]
shallow seas, accumulated vast amounts of this vegetation, sunk it
beneath the sea, roofed it over with sand, compacted the sand into
rock, and changed this vegetable matter--the products of the
sunshine--into coal; and when it was ready, lifted it once more, all
garnered for the use of men, roofed over with mighty mountains. We
mine the coal, bring out the heat, raise the steam, drive the train,
so that in the ultimate analyses it is sunshine that drives the
train. These great beds of coal are nothing but condensed
sunshine--the sun's great force, through ages gone, preserved for
our use to-day. And it is so full of force that a piece of coal that
will weigh three pounds (as big as a large pair of fists) has as
much power in it as the average man puts into a day's work. Three
tons of coal will pump as much water or shovel as much sand as the
average man will pump or shovel in a lifetime; so that if a man
proposes to do nothing but work with his muscles, he had better dig
three tons of coal and set that to do his work and then die, because
his work will be better done, and without any cost for the
maintenance of the doer.
Come down below the color vibrations, and we shall find that those
which are too infrequent to be visible, manifest as heat. Naturally
there will be as many different kinds of heat as tints of color,
because there is as great a range of numbers of vibration. It is
our privilege to sift them apart and sort them over, and find what
kinds are best adapted to our various uses.
Take an electric lamp, giving a strong beam of light and heat, and
with a plano-convex lens gather it into a single beam and direct
it upon a thermometer, twenty feet away, that is made of glass
and filled with air. The [Page 32] expansion or contraction of this
air will indicate the varying amounts of heat. Watch your
air-thermometer, on which the beam of heat is pouring, for the
result. There is none. And yet there is a strong current of heat
there. Put another kind of test of heat beyond it and it appears;
coat the air-thermometer with a bit of black cloth, and that will
absorb heat and reveal it. But why not at first? Because the glass
lens stops all the heat that can affect glass. The twenty feet of
air absorbs all the heat that affects air, and no kind of heat is
left to affect an instrument made of glass and air; but there are
kinds of heat enough to affect instruments made of other things.
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