, 1877-05-16
II TELEPHONE.
From the NeaO York HeraJG.)

The possibilities Of the electric telegraph
have never been more strikingly illustrated
than in its latest adaptation to the transmission
Of musical sounds and the tones Of the human
voice. The wonders of the telephone eclipse
any that have hitherto marked the progress Of
the science OF electricity, and when reduced by
the skill and perseverance Of inventors to the
level Of common use like the ordinary tele.
graph, IL will prove one of the most important
and useful Improvements in the art of telegra.
phy. Communications between distant points
will be no longer liable 10 the misinterpre.
tatious lnseparable from the signal system, and
instead of being transcribed and forwarded e.
written matter, will become conversations Be-.
tween individuals perhaps thousands Of miles
apart, in which the voices of friends will ba
recognised, and even the sigh Of grief or tie
laughter of Joy will be heard as distinctly as If
those communicating with each other sat in
the same apartment. Hy means of apparatus
operated by electricity and the ordinary telo.
graph wire it is possible to transmit g fac-simile
Of writing and Of the outline Of a picture. This
success was deemed Tho ful6lneut If the ulti
mate expectations of electricians regarding tha
uss Of the telegraph for the reproduction Of
precise motions and their effects. But now an
entirely new field for invention and application
* opensd up by the discovery that sound, tone,
music, the utter&nceS Of Tbs human organs Of
speech, ;he Ioudest reports and tbs faintest
tinklinQa can be reproduced at c distance Of
many hundreds OF miles.
sounl d the faai eEact produced on tbs
ear by G vibration or impulse transmitted
through any claatio medium. aerial, liquid, or
sofia. When e sudden Blow is delivered TO
the ar, 20 when g canon Is fred or an electric
spark il 'n.de 70 pass. the imQalse is prOpaga-
tsd through the yir anG ultimately reaches the
car SIS . noise. Tbs cCcrEy Of The shock Of
propagation determines ths loudnega of the
noise resulting. Tbs can be simply Illustrated
by asking thu reader 10 consider tho effect OF
dropping q psbblo into the centre Of a LARGE
pond Of still water. Where The pabble strikes
tho surface a shock is administered, and the
surrounding water is disturbed in equilibrium.
Immediately a circular wave is developed,
which extends more or less rapidly from ths
point Of it's generation, and continues to propa.
gate itself, as It were, until it meets with soma
obstruction, say the margin ofthe pond. Now,
In like manner a wave is propagated in a volume
Of air, and is transmitted from particle to par.
ticle Of The atmosphere uDtili il III eets with some
obstruction, as in the case Of the water wave.
When it meets with a resisting surface it is
DETECTED, and the shock Of DETECTION Dropagates
another or return wave, which the ear appre.
ciates ia the phenomenon of echo. But in
applying the foregoing illustration it must be
remembered that noise is the result of one i'm
pulse-the impact of one layer of air against
that one next outside it. It has no wave length.
To produce a wave of sound as distinct from 2
noise, it is h necessary that the impulse which pro.
duces the latter be repeated periodically that
10, q certain number Of times per second, say
100, then it is clear that the particle Of air first
affected will be also affected by an impulse
every ons.hundredth part Of a second, or will
vibrate 100 times per second. AS the original
impulse is propagated at the rate of l,1oo
feet per second. each succeeding impulse or vi
bration follows the proceeding one at the dis
lance of eleven feet, which is the length of the
waves of sound when the vibrations occur at
100 per second. This sequence of vibrations
of the air produces a tone as distinct from a
noise The structure of the ear is especially
adapted for the reception of impressions produ-
cad by sound. A thin membrane, called the
tynpantuim," is strained across the passage
Of tiisf ear. dividing the organ into outer and
inner portions. This membrane vibrates
With the aerial impulse or seunc wave. and