New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1878-03-25
TIE LECTURE.

and disiinctness.
THE LECTURE.
LADIES AND GESTLEMES: I suppose that
most OF those who have come on this occasion have
gathered themselves here tor the simple purpose Of
hearing The clobrat ID machine OF r Edison talk Afera
while we shall think, that the speaking phono.
graph or talking machine n probably the greatest n-
ycntlon In acoustics the greatest acousca phcnon
Of ths century. IN ORDER however. % appreciate
the mechanism by means OF witch the human voice 10
reproduced IN such extraordinary manner. We must
take rapid glance ~ the physics and physiology Of
hearing.
The physics and physiology OF hearing-lise that OF
siSht-nlt be studied "a two ways; Er.t ~ Oh, tho
actual millions which necessary 60 produce sound
AMI then the manner M which sound Is appreciated ~
the individuals In other words must become Tally
acqlar,cd with the objective aud Subjective phenomena
ana thon brng these two together r. tc nrst place.
both light sound phases OF motion. Light con-
sisis ~ know OF uniulht0ns or waves. and sound
consists Of unduat)ns waves ais0 bat the uudula-
tions or waves Of HIGHT dicr IN the which they
travel in which they make their iournoyas The light
waves arc propagaled from luminou. body, aud tako
Their direction la straight lines from the luminous BODY,
b.. the direction mO0l oi The PARTICLES ~ luminous
ether arc rshau e "a th8 direction oi tie propaga.
ton on the other hand, sUuutWHycs are transmitted
in a direct Lac. end We have very much ;lc same phe
nomcla "a sound have ~ waves ~ waters that Ia
q say whom q stone Is thrown into tho water you viii
notice that fron the point wRerc TIE Stone
mpncts upon the water series OF waves starts, sphcF-
Teal IA fOrt and sent IN a directions outward In
order e. appreciate tlc manner IN which these waves
pass In tho atmosphere p.c1usc 10 u necessary wo
should nave soao medium 90 propagate or transmit tho
waycs we will make ne, "a mOment oi ltile mechan
teal conlrvauce or otlgram which give, idea u
tle propagation o' fuIud Tn waves % solld they
appear ~ tie aimo.poTc, consist ~ rafhctlls and
COMBINATIONS OF The ar sound can Dee produced by
motion or vibrations solid bodies ~ well a' he the at
mosihert anl We shan study th' sailro that
tie car can appreciate the sensation u sound SIMPLY by
the vibrations OF sold bodies provided tle .1ld bodies
are able 20 transmit the vibrations directly 90 the por-
lion 81 the which receives the impressions. Bat for
the general condition of SQUAD must have air We
must have substance TO carry the waves from one
par t. the other and IN general every body hen that
produces q SOUND earth, unless Il be- the direct
transmission Of the body ss Up these waves and hey
are carried through the air.
Tue MOTION or sOUND-wAvEs.
ITere we have illustrating the screeni what would
represent the Of sound-tAcse hGht ponts-and.
a. told YOU the motion Of the particles. which We viii
study more definitely IN moment Is back ara and Tor
ward Now when sound Is produced, the air = thrown
into lust the vibrations that here. Each one OF
those waves makes Its excursion NJ ana dowa In all
directions. These waves have actually been SEEN
physic.t OF the name OF TOeplrr enabled, by caus-
ng sound from the electrical discharge. 10 see rho
waves Of sound and he found that these waves could DO
reractcd reflected. ard tat they oheycd all OF the
laws which found In hight. Ia addition 70 THIS he
found that those spherical. and have an
idea OF the o me sound OF these waves as
spheres overlapping each other each made up oI Itte
pariiccs Of ali. aud these particles vibrating backward
and forward. Now viii ty an experiment Here
we have sitllkc formation the screen and In this
We will be enabled 10 SEQ the vibration OF
rho particlcs Each leaves its position only for
n short distance. The intensity the loud
ness ot the sound depends upon the distances
each OF these particles moves. BY the generation Oh
the sound II moves the position II has at rest TO
certain position and back again IN an opposite direction.
As you see represented on the screen 30 far hen FOL
the generality OF TIE sound waves. There are a great
many other points which we have to hurry over to
night IN order TO get general and, unfortunately some
what sluerlcal idea of the whole subject
Sov; take into consideration the manner In which
these waves be thrown into action Thunder s pro-
duee as know by electrical discharge In the at
nosohcre. Tie electricity bling driven through the at
osnbere with tremendous rapidty the air 10 be
hrown Into vibrations which cause the sound we recog.
r,ze n, thunder The electricity Is the lightning, tho
souud is the thunder II Ggate any body which Is
solid we then produce certaiunumber OF vibrations in
the atmosphere, ana these correspond 10 the Vibrations
of the body II We a column Of air ~ uDate IN
tubc We produce a musical tone. which Is simply duo to
vibrations Of the Ia the confined space OF the tube
timing rk IN sounding simply mechanical disturb
ouce of the air and when In vibration II produces What
IL known as musical tone. We shal see thas
the musical tone depends upon certain pecu-
uar conditions OF vibration, and we shall sec
also tnat noises differ from musical tones simply
they can be referred TO other pocnla-ies OF ybra.
ton In sounding fork have pleasant tone to tho
ear THIS mechanical vibration OF the air by the vi
brtiop of an tic BODY viz, the steel 81 which the
fork is composed In o moment We will try another ex-
perment where We throw into vibration column OF ar
confined in a tube. We also produce Vibrations by
a succc sson " puh Here l. little instrument calico
siren" II has disk which Is perforated. and an air
cbomber There is compressed air IN the cylinder
and M is turned on the puts OF air escape. causng
70 come opposite the opening In this archainber very
ronidy and evenly and there is succession Of puns
which can be heard near by and pretty soon tone VIII
break forth Here tue lecturer illustrated his meaning
by the apparatus feIed TO, and was appsuded Tor the
success OF his experiment.
SOUND PRODUCED ~ TUBES
The mechanism Of the production OF Sound by this
,ber little instrument Is lrst the generation OF hydro
con by decomposing water with the aid OF acid There
IA very ne point from which the hydrogen burns IN
roduced into glass tube. The air passing M through
tbe tue becomes heated aud 10 thrown into vibration W
the fame the air being thrown up aud down. Hwe
have very large tube hall have very deep tone'
and shrer In proportion the size OF the tube dim-
sics Tho vibrations are rapid in the large as IN
the smaller tubes, In the latter case the waves nemk
smaller and consequently lighter IN tonc Inc oruhnty
elect produced la The organ pipes u course We unue
stand. Here have simply the puus VI al WINCH p~ss