Wood County reporter. [volume] (Grand Rapids [i.e. Wisconsin Rapids], Wis.) 1857-1923, 1873-01-23
CURIOSITIES OF SOUND.
By F. R. GOULDING.

By F. r. GOULDING.
Can there be sound where there is nc
hearing?
"Certainy," is the prompt reply of
some; s'fOr what is sound but vibra-
tion?"
Certainly not" is the equally prompt
reply of others; ''for is not sound SEN
sation?''
1t is both, and therefore both parties
are right; the last popularity, the first
philosophically. No one, whether phi.
losopher or otherwise, questions the fact
that where there is the sensation of hear.
ing there must be sound; but the minds
of some fasten so exclusively upon the
sensation" as to forget that its proxi-
mate cause is equally entitled to the
name of sound "a notable instance ..of
which is to be found in Worcester's Die
tionary, excellent though it be-, and there
fore it may not be amiss ii, while adher-
ing faithfully to the theme noted at top,
we amuse ourselves with a few facts
going to prove the especial correctness of
the first reply.
Sound, by which we now mean the
vibrations OF a sOnorous medium produc-
ing upon the ear the sensation of hearing,
can be seen and felt as we'll as heard, and
can be seen Or felt sometimes when it
cannot be heard. Who has not felt the
back of his pew in church quivering with
certain tones OF the preachers voice, or
with certain notes of the organ? Even
the celebrated Julia Brace, though stone
deaf, as well as stone blind, could distin-
guish her companions, it is said, by the
peculiar vibrations attending the tread
and the voice of each. And, during the
recent war, it was not unusual, with
those who understood the art, to watch
the progress of cannonade, too distant
for the ear, by means of hole bored in
the ground, from the sides of which
loosely -adhering particles would be shak-
en- down by the inaudible sounds of the
cannon. The beautiful experiment of
| making sounds, .. e., s0norous vibrations,
visible by means of fiddle-bow drawn
across the edge of a glass or metal plate,
clamped in the middle and strewed with
sand, is well known. And those who are
familiar with that exquisite instrument,
the glass cups, invented by DR.. Frank
lin, and named by him the Harmonicon,
will recall with pleasure the beautiful
system of wavelets upon the surface of
the water caused by the vibration of the
musical cups, and will easily believe that
a close study of these wavelets might al,
most enable a keen-eyed observer to
determine, by sight of the notes, to which
they respectively belong.
But the most impressive illustration we
have is a wonderful device owed mainly
| to the scientific ingenuity OF
Professor Tyndall, Of London.
After experimenting long with those
musical flames" so well known to
science-fames which not only utter a
kind Of music as part of their being,
but which leap into new life on the
| sounding before them of certain notes,
rising, and falling, and quivering, as the
| notes vary-he at last devised a flame
which not only recognized music, but, in
part, recognized the alph06et. for, as he
quoted poetry before it, the thing seemed
almost intelligently to respond to the
sound of certain letters, boring to some,
7aodd5ng to others, making profound
| obelsance to others still. while some it
left unnoticed. This marvellous little
agent he has many time exhibited pub
llcly IN his lectures on sound, and he calls
| it his ''VoWel flame"
Another fact tending to the same gen
eral point, and a curious one it is, is that
some persons of excellent hearing in the
main are insensible to notes of a certain
pitch. AS in sight, there is what is called
color blindness" in which the persons
affected can see shape and shading, but
| are insensible to particular colors; so, in
hearing, there is what may be called tone
| deafness, in which the ear is sensitive to
all sounds and mOdulatiOns except those
OF certain degree of acuteness Public
attention was first called to this fact by a
paper Of DR.. WollastOn lin "Philosophi-
cal Transactions" of 1920 and it was
| afterward closely studied by various men
| Of science, among whom was the elder
Herschel. Wollaston, while studying
the pitch Of some very acute notes, was
SURPRISED to find that his friend and com
panion was wholly insensible to them
His sense of hearing was perfect
up to four octaves above the middle Z of
the piano, but beyond that it suddenly
and perfectly ceased. The chirp of the
English sparrow was barely within his
limit Of addition, but the squeak of the
bat was beyond it. Sir John Herschel
says: Nothing can be more surprising
than to see two persons, neither of them
deaf, the one complaining of the penetrat-
ing shrillness OF sound, while the other
maintains there IS no sound at 0N" Pro
fessor Tyndall says: i" l myself noticed a
case of shOrt-audition range in crossing
VIZ W CASClu All III COIllpduy Will ITlenu.
The grass on each side of the path swarm
ed with insects, which to me rent the air
with their shrill chirruping. My friend
heard nothing of this, the insect-musc
lying quite beyond his limit of addition. {"
This 'limit of audition,' alluded to by
these distinguished men, has been most
carefully studied, both by theory and ex-
pertinent, and the result is as follows:
The lowest note audible by human ears is
caused by sonorous body which vi
brates 80 times in second, and is the same
in pitch as that of an organ-plp 80 x feet
long, and open at both ends. The
''sound-wave"-for it must be remember
ed that the undulations of sound, light,
heat, etc, must be more or less con
ceived of under the analogy of water-is
also calculated to have diameter-or, as
it is usually termed, length-of 80 feet.
So that, in measuring the lowest note
audible by human ears, the number 80 fig
ures three times. But, though the lower
limit is thus easily ascertained, not so with
the higher. By some it has been fixed at
$500 vibrations second, by others at
$4,000; and by others carried up as high
1900. The shortest sound. wave known
is estimated to havea diameter, or length.
of half an inch. Assuming this as cor
rect, and then breaking up the distance
overpassed by sound in a second viz. t.
1875 feeD into half inches, we haxe q, 600
vibrations per second. These calcula-
tlons, 1t must be admitted, are very unre-
liable except as approximations to the
truth but such have been the triumnhs