Wood County reporter. [volume] (Grand Rapids [i.e. Wisconsin Rapids], Wis.) 1857-1923, 1873-01-23

/ class, associated with the uelocity of sound.
Whoever listens to distant music will OBJ
serve that all notes, whether high or low,
soft Or loud, travel with exactly the same
velocity, and that even the accents and
the intervals keep the same time. 1t is
so with all sounds passing through the
same medium at the same moment; what
ever their nature, their velocity is the
same. 4e allow few little changes of time,
place, or circumstances, and the rate is
found to be exceedingly variable. 1t
changes with every change OF the wind !;
it f1uctuates with every rise and fall of
the barometer; and, as to temperature,
it is as sensitive to it as the mercury or
spirits OF wine in a thermometer, showing
difference of / IA feet for every degree
of Fahrenheit. Important as these facts
are, they were most strangely ignored, or
at least overlooked, in all the earlier at
tempts to fix the average velocity Of
sound-so much SO that the blunders
were almost laughable. One experiment.
suppose, time which reduced his rate to
the lowest possible notch, and probably
making mistake even then, informed
the world that sound travels at the rate
of $50 feet per second. Not long after
ward, Dutch philosopher reported it at
1,474 feet. The Academy of Science at
Paris fixed it, for time, at 1888. The
usually exact and careful Newton put it
down at 96S. During the first half of the
present century, all students of physical
science were taught that it is l, 442 feet.
more careful measurement, however,
made by different parties at different
times and places, and with all due allow
ance for the disturbing influences of
wind, moisture. density, and tempera-
ture, has established the velocity, in dry
air and at the temperature of freeZing
water, at 900 feet per second, and at
1 ,125 feet in air at the temperature of GO
deg. Fahrenheit. This is the present re-
ceived rate, which the late Sir John Her
schel declared is mo doubt within award
of the truth, and probably within foot. 4"
But these facts and figures are true
only of sound travelling through air. It's
velocity through water is 4, 7OS feet per
second, being more than four times as
great as through air. For example, if
two bells be struck at the same instant
one in the air at the distance of 1875
feet, and the other in water at the dis
lance Of 4,70S feet-t1ey will both be
heard, second atterward, by a person
who has one ear in the water and the
other in the open air, But there will be,
at the same, considerable difference in
that travelling through water will be far
less loud and less acute. Indeed, sound
passing through water will not only travel
much faster, but much farther, than
through air. A pair of stones struck to-
gether under water, can be heard distinct
ly, at half miles distance, by a person
whose ear is immersed in the water, when
the same stones, struck as violently in
the air, could not be heard at half the dis
lance.
Still more remarkable are the facts at
tending the passage of sound through
aco0d. 1t is usual to meet with the state
ment that the scratch of a pin at one end
Of piece Of timber can be heard by an
ear applied at the other end. But this is
by no means all that may be said in the
case. The writer was once present where
five large beams lay, end to end, continu-
ously on the ground, with their extremi-
ties in heavy contact The opportunity
tempted him to try the experiment, and
the result was, that not only could the
scratch of pin or the ticking of watch
be heard from end to end of
each piece of timber, but the
scratching of a small pen-knife
was heard distinctly through tie achole Sc
raes, at the distance of several hundred
feet, for each piece was about fifty feet
long. The velocity Of sound travelling
thus through wood is said to be eleven
times greater than through air, or at the
rate of more than two miles and a quarter
per second; while through iron and glass
it is seventeen times greater, or about
three miles and three tifths per second.
The astonishing passage Of sound along
thread or small cord is familiar to almost
every one, but not SO all the associated
facts. If the ears be stopped with the
fingers, so as to exclude all sounds from
the air, and large thread or small cord
be wrapped around the fingers, suspend
ing sonorous body of any sort, the sound
passing to the ear along the cord, when
the body is struck, will be almost deafen-
ing. A common fire shovel or an iron
ramrod, will sound like heavy cathedral
bell. Yet, strange to say, a h0nd-6eU, sus-
pended and struck in like manner, ex-
ponds all its sound in the air, but sends
none to the ear; the vibrations of the cord
can be distinctly heard, but not those of
the bell. Again, the notes produced by
these vibrating bodies upon the air are
very different from those conveyed
by the cord. For instance,
carpenters iron square, suspended
at the angle, and struck two
thirds of the way down, gave through the
cord the note of the loseest Fof the pi,no.
while in the air the note was the fifth r
aboye. The one almost deafened with its
heavy bass; the other was almost painful
from its shrill treble.
Another curious fact is the cast number
Of sounds W1tich enter tie ear eyery moment of
life, and which are all unnoticed, EXCEPT
when receiving particular attention The
writer pens these lines about nine o'clock
of cool summer night. A moment since,
he was conscious of no sound but the
busy scratch of his pen; bat, qiy-
ing ear now to all the sounds
within hearing, he himself is amazed
at their number and variety. Nearest
his ear is an unusual hum from his kero-
sene lamp; few feet distant are heard
the tlckings Of mantel clock, under
meath which, in the chimney, two crick-
cts enliven the room with their merry
chirruping; in an adjoining room is the
gay prattle Of children preparing for led;
from servants room in the yard come
the softly blended notes of an ACCORDION,
while on the neighboring troes a night
locust saws the air, in concert with fif-
teen or twenty katydids; and on the
ground small regiment Of :oads unite
their discordant voices, at the same time
that the buzz Of a mosquito gives him
warning of an intended bite upon the
hand, and at the open window, attracted
by the lamp, "beetle wheels its droning
Hight. These ten different sounds-or