The Toledo chronicle. [volume] (Toledo, Tama County, Iowa) 1873-1924, 1875-10-07
Sound, Light and Heat,

- q H
THE passage of light through the air,
as is well known, is almost instantaneous;
that Of sound is comparatively slow, at
the rate of 1903 feet per second in dry
air, but its velocity increases with an in
crease of temperature. This rate has been
determined by actual experiment. Two
n were placed IN heights in sight
of each other; on a calm, cloudlesS night
twelve successive discharges were fired
from each piece, and by means Of accu-
rate, delicate watches the time interven-
ing between the flash and the report was
carefully noted, giving the result already
mentioned. 1t is noticed that the more
violent the sound the quicker its trans
mission, and sound is conveyed much
more rapidly through earth or water than
through air. This is partly due to the
more compact nature Of the substance
through which the sound is transmitted.
While the lateral transmission Of sound
is often very extended, the upward is no
less remarkable. The capacity for APP
preciating sound is very different in va
rious individuals. A we ll-trained ear
can catch a sound caused by fourteen vi
brations per second as well as one caused
by 4S, 900 vibrations, out SO well trained
an ear as this is rare. The distance at
which sounds can be heard depends on
their intensity. The report of a volcano
at st. Vincent was heard 800 miles away,
and the cannonadingat Waterloo was dis
tinctly audible at Dover. As sound is trans
mitted better by a passage from a denser to
ararcr medium, we might naturally expect
that sound would penetrate to high re-
gions in the atmosphere. Aeronauts have
proven that the whistle of a locomotive
could easily be heard at a height of
10000 feet, and the barking of a dog at
5000. The croaking Of frogs in aswamp
was easily d~istinguishable 5000 feet up,
and even the chipping of teld-crickets
was audible at the same altitude.
Sounds from the earth travel much
further into the atmosphere than atmos'
phcric sounds sent downward. While
the aeronaut can hear mems voices at a
distance of 1000 feet below him, he is
compelled to come within 300 feet ere
they can hear him. Clouds, when i'm
mediately surrounding q balloon, tend to
intensity, but, when far below, totally pre-
vent the transmission of sound. 1t is GER
tain that the ether which intervenes be-
tween our planet and other worlds is not
capable Of the transmission Of sound; the
sun, moon and stars might be shivered to
a thousand atoms and not a sound of the
mighty crash greet our ears. In regard to
our ~aeronautic experiments it is stated to
be singular to notice the echo which may
be observed in passing over a sheet Of wa
ter, as the latter by its smoothness affords
the best echoing surface known. The
color of the atmosphere has often been
matter of dispute, but it is now generally
agreed that the blue tinge is owing to the
presence of minute globules of aqueous
vapor in the upper regions, and not, as
was formerly supposed, to the blue color
of the air. In~tcrplanetary space is per
fcctly black. The warmth and GOODNESS
of the air have also been objects OF the
closest attention, and the extremes OF
temperature noted with the greatest care.
In all extremes, however, both Of heat and
cold, a slight adjustment of clothing and
diet is all hat is necessary to preserve
human health in its highest condition.
The grade of decrease in temperature, on
ascending from the earth's surface, is
found to be by no means constant, as was
formerly supposed, since a great many &C
cidental and local circumstances easily
change the ratio. Enough is known to
make certain the factthat the temperatures
al high elevations are nue. more constant
than on the surface of the earth.-"1he
Aerta1 Wo11d," By G. Harting.