f what has
recently been learned as to the actual warmth which the sun possesses
and of the prodigality with which it pours forth its radiant
treasures.

I number among my acquaintances an intelligent gardener who is fond of
speculating about things in the heavens as well as about things on the
earth. One day he told me that he felt certain it was quite a mistake
to believe, as most of us do believe, that the sun up there is a hot,
glowing body. "No," he said; "the sun cannot be a source of heat, and
I will prove it. If the sun were a source of heat," said the rural
philosopher, "then the closer you approached the sun the warmer you
would find yourself. But this is not the case, for when you are
climbing up a mountain you are approaching nearer to the sun all the
time; but, as everybody knows, instead of feeling hotter and hotter as
you ascend, you are becoming steadily colder and colder. In fact, when
you reach a certain height, you will find yourself surrounded by
perpetual ice and snow, and you may not improbably be frozen to death
when you have got as near to the sun as you can. Therefore," concluded
my friend, triumphantly, "it is all nonsense to tell me the sun is a
scorching hot fire."

[Illustration: THE SUN: FROM A PHOTOGRAPH TAKEN BY LEWIS M. RUTHERFURD
IN NEW YORK, SEPTEMBER 22, 1870.

Professor C. A. Young, writing to the editor of MCCLURE'S MAGAZINE,
pronounces this "still the best photograph of the entire sun" with
which he is acquainted.]

I thought the best way to explain the little delusion under which the
worthy gardener labored was to refer him to what takes place in his
own domain. I asked him wherein lies the advantage of putting his
tender plants into his greenhouse in November. How does that preserve
them through the winter? How is it that even without artificial heat
the mere shelter of the glass will often protect plants from frost? I
explained to him that the glass acts as a veritable trap for the
sunbeams; it lets them pass in, but it will not let them escape. The
temperature within the greenhouse is consequently raised, and thus the
necessary warmth is maintained. The dwellers on this earth live in
what is equivalent, in this respect, to a greenhouse. There is a
copious atmosphere above our heads, and that atmosphere extends to us
the same protection which the glass does to the plants in the
greenhouse. The air lets the sunbeams through to the earth's surface,
and then keeps their heat