New-York tribune., 1841-12-30

Blanc. he found it exrreusIy diiHC0'' @ ~
.r,f heard by his companions u they "'''
l;,tle distance from each othet anu ''''
49, hoo, proyed in the case OF the himneia;a
Mountain H. ..;-
in, Of sound, skill il may be conveyed in other
,yay.; and a beautiful experiment tried at Paris
.bows that metal batter conductor OF sound
than the air A very long metallic tube was pro-
vided and one end of II was struck while en ear
was placed the other end TO hear the sound
FIVE distinct sounds were heard one conveyed By
he metal and the other by the air, and the fret
was heard the soonest by certain short interval.
All substances hch Will convey sound must be
more OF less elastic aud in proportion as :he elias
ticity produces regularity Of vibrations, it Is found
hat il acquires the character of a musical sound.
In the examination Of sounds there three dis
,nctions made which known by these names.
(althoueh have no very good English terms for
hem )-the pilch, the infeasify and the quality.
The pitch OF sound is waat !, called the note in
music for instance. the note produced by striking
particular key OF Il pano-ioric l. ot a certain
ptch-either higher or lo,ser The intensity o(
sound is name merely expressing lis degree OF
oudne-. it j. eyiden, tina, sound may have the
,arne pitch a. another and still be OF very dit
iersnt degree of intensity: thus the same n-,e ot
. pianoforte il struck first with the soft pedal up
md then down will be OF thei same pitch but OF
different Intensity The third character Of sound
its quaiity, which l. hard 10 describe, we
nave no good terms exprcs, what 1t means.
can only explain II by example. If the string
Of guitar be struck, it viii produce certain note
in the musical scale; The string OF pi4no-iorte II
struck may produce a note OF the same pitch and
the same intensity; but the TWO will still be OF very
different qualities. The same note on hute or
claronet and on hagtboy, though ii may be OF
The same pitch and intensity in all the cases, will
,e Of very different quality. II the science OF
Acoustics sufficiently advanced, ought to
nc able to deiine precisely the mechanical circum-
stances by which all these distlngU- -hed from
ano,her-to state the number of vibrations in
the air requisite for each If hammer be struck
upon an anvil, upon stone and upon piece OF
wood, the sound in the three cases will be OF dif-
ierent qualities; bat if you ask the scientific or
mechanical distinction, unable TO answer;
,hough If the science sufficiently advanced,
xe ought to be able to tell the number of vbra-
lions in each case but at present this cannot lie
done.
Sounds, in order 20 be musical mus, be produ
ced by vibrations which must be continuous and
regular; they must be caused by continued sue
cession OF equal and regular vibrations Of the air
caused by the sounding body. Unless this be
s0 the sound will not be musical. The object
in the construction OF musical n,lrumcns, then,
must be to procure bodies which will cause, under
all variations, equal numser OF vibrations in an
equal time. The first and mos simple of these
bodies and the earliest employed were musical
strings, and these appear the easiest way OF
explaining popular audience the theory OF mu
scal sounds. | shall continually refer to them III
the string OF violin or guitar be drawn from IL
position Of rest and allowed TO return, it will not
stop at its position of rest but will pass beyond it
rhen s elasticity viii cause il to pp.' 10 the opPo
lite side, and thus 1t will conuu- 10 ,ibrae from
side 10 the o;her; and evrry vibration OF the |
.trng im9artS To the air corresponding pulsa |
tIon. The sriHg al hrst will pass to greater dis
fance from the position Of rest than afterwards
but the time required for each vibration will be
equal, whateverbe the length If The vibration. So
long the string goes in It's vibrations, pulsa
lions communicated to the air and thus con |
eyed TO the and the number Of vibrations for
sac second will always be the same for the same
string. That each vibration, whether longer |
shorter. will require the time, will be evident
from this consideration: that when we draw the |
'tring fro its position of rest in the first place,
The force with which it tends to return is much |
greater than when, by the resistance of the air the
vibration Of the string diminished: it will conse
!ueHiiy return Will gItdttI III tIP IoTlItl
than in the latter. 1t is found that this admits
If strictly mathematical demonstration but thi,
t.! not of a character to be exhibited to popular
audience it is sufficient state that it i, capable
Of geometrlcal demonsiraion-iha the time taken
N the one case is precisely equal 20 that required
IN the other, because tAe greater the space be |
2assed over the more energetic the tendency to re-
urn, and consequently iI!e velocity is greater in
'hc same proportion. Thus when we pass the
5ow of violin one of It's strings, whether /
with greater or less force, whether the vibrations
produce loud, or light and whispering sound, /
still the number of vibrations for each second Is in
both cases the same. Tne sounds will not differ in
pitch but in intensity. In the same way, if the |
string of a pianoorte be- struck with greater
less force. the divergence in the former case Is !
:, ,eater than IN the other, and tho therefore
differ in ioudnesS. The same principle applies TO
al the notifications of musical instruments, ii |
they be played they ough: 10 be, which, TO say
the truth, is not always the case-especially with
III, flute. Judge OF musical instruments la,
said that it Is physically impossible play the flute
m tune that il note be correct another Will |
not; ana this is, To some extent, hi least, per
tectly true; for the volume of air put into vibra-
ing NJ t'on depends, no inconsiderable extent.
upon the enab0achUre or mouth which il constantly
varying so that the same lingering may actually
produce different notes IN different cases. This is
an lncurabr defect which attaches TO the flute
tha, the vibrations produced are uncertain. This
is not the case with s,ringcd instruments.
Having ,hus explained in general way the
principle which the musical character OF sound
depends will now endeavor To explain the cir
cumstances on which the effect of combined .ound-
depends this is simple and admits of s,rictly
scientific investigation. If musical string be
divided in the centre-!or instance ii the string of
violin, between the bridge ard the nut. be
Ii. teI ND -, L.