, 1876-11-04

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for instance, in its combustion, is capable
of elevating one hundred pounds in
weight four and half miles high. This
is the mechanical equivalent OF the heat
it is capable of giving out, though our
imperfect machinery is incapabIcIof utiI-
ising much more than one fourthIot that
amount Of heat, the rest being lost by
friction, radiation and convection.
But some of my young hearers may
remark that motive power may bc OBJ
tained without food and WITHOUT fuel,
and that much of our machineryis driv-
en by the force Of falling water. Docs
that torce too come from the sun Tn.
doubtelIy it does. The heat of the sun
combined with the water OF the earth
makes vapor, the vapor condolences INTO
clouds which the winds drive tc all quar-
tiers of the globe the clouds give back
their water in the form of rain, the rains
form the rivers. the rivers drive machin-
cry, and the falling waters give out pre-
ciscly that amount OF motion that Is the
mechanical equivalent Of .he heat they
drank in from the sun. How bcauti'
fully our great poet, Longfelow, perhaps
the greatest poet Of the age, alludes to
what the poet and the seer OF science
behold in the falling rain. Besides its
profit to agriculture he says:
"Thcse and fur more than these the poet sees
He can behold Aquarius old
Walking the fcnccleSs fields ofnlr;
| And from each ample fold
OF the clouds abo ut him rolled,
Scattering everywhere, the showery rain,
As the farmer scatters his grain.
He can behold things manifold
That have not yet been wholly told;
Have not yet been wholly sung nor said;
/ For his thought, that never stops,
| Follows the water drops
| Down to the graves Of the dead;
Down, through chasms and gulis profound,
TO the dreary fountain head
| OF lakes and rivers underground
And he sees them, when the rain is done
On the bridge of colorS seven, a
| Mounting up once more to heaven,
Opposite the setting sun.
Thus the seer, with vision clear,
Secs forms appear and disappear
In the perpetual round OF strp'
Mysterious change;
From birth to death, from deS
From earth to heaven, from 3
Til gllmpses, more sublime.
OF things unseen before
Unto his wons.stl.s;s2l''
The universe, us an imh
Turning, turning, turning.
In the rapid and rushing river
Were the earth peopled is'
capacity, still the water Z .t II
affords would be ample to III all
the labor demanded to supply wants
OF man, could it be properly applied
Ampcre computes that the fal s OF Nj
agnra alone give power enough to drive
all the machinery in the world and more
than fifty times enough to propel all the
machinery in the United States.
Every particle OF force that body
gives out is but the expression or equiv
alent of some force that it has received
Force can neither be created nor de-
stroyed, and thus the old illusion OF the
perpetual motion is completely dissipa-
tel. How enormous is the force the
earth receives yearly from the great cen
tral luminary! Herschel computes that
the annual amount Of heat that our globe
receives from the sun is sufficient to melt
crust of ice ninety.s seven feet thick all
over it. Now when we reflect that,
compared to the great globe OF the sun,
| our earth Is but little speck, anu tha1
situated at distance of about ninety
three millions OF miles, we may form
some faint idea of the immense amount
of heat the sun is perpetually radiating
into space. If force cannot be created
where does this enormous supply come
from1 Whence comes that streaming
power, of which but an inconceivably
small fragment confers all its life and
motion on our earth of which but a
little fragment gives life and motion to
all the other planets, while by far the
larger part--indeed almost the whole
we may SAYS scattered into the bound