New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1883-10-22
SOUND VIBRATIONS PHOTOGRAPHED.
pICTUREs IN ONE TIVE TY-FOUR THOUSAND
AS COD.

PICTURES IN ONE TIVE TY-FOCR lHOCSANDIi OF
AS COD.
Photography appears to be running a race with
electricity in curious developments and novel ap-
plicatIuns. George q. lockwood, the well-known
photographer, has just achieved the remarkable
feat OF pmOtographing sound waves lnStantaneouS'y
The instrument by which the sound wave was rep
resented made visible IN ITS effect Is new tee-
phone, the inventor of which has obtained from Mr..
lockwood perfect ocular dcmn3Strt-
ton of its vocal repeating action. The
vibrating diaphragm upon which the voice is pro-
ie,trd has fine metallic point mounted on the cen
ire of its reverse side This point meets the pointed
end of Il conducting wire 50 nearly that whcn at
rest the interval between the two points can be dis
covered only through strong lens. The thing to
be done was TO show in picture OF the instrument,
or rather in a series of pictures, the alternate con
tact and separation of the points from the Nlhld-
tiois Impaired to the diaphragm by the voice, IN
volVing the closing and opening Ol the electrical
circuit and the consequent reproduction OF the same
rate of vibration in the receiving instrument at tine
Other cld of the line. In considering tins problem
Mr. lockwood found himself indebted to HIS re-
collection of All experiment by llcrschel In photo
graphing Tor dagucncOtyPIng) with the electric
spark Herschel caused fOur-sidcd prism Of wood,
around which picture was pasted, to revolyc NJ
hi oh sDeed as in "a turning lathe. BY Illuminating
this revolving picture with the electric spark I'm
total darkness Otherwse he obtained photograph
of il as standing still AT that instant IN IT'S TeV0u-
tiOn when the spark flashed. In describing his eX-
pertinent Mr.. lockwood said
4" WheatstOne measured the duration of the e lee
tric spark as Onc-twcnty-fOur thOusandth Of a
second 1t would follow that any Vibration not
quicker than this might be arrested on the photo
graphic plate AT any point III It's travel. NhcrcaS,
according to the Investigations OF Plateau, the dur-
tiUn Of successive impressions on the human eye will
average half second the electric spark might sep
arate and distinguish phOtOgraphically waves OF
which II 900 impnge on the retina while the first
of them is still lingering there; IN other words,
IL 900 practically all at once. Now the vibrations
or waves of air that yield the respective tones or
pitches of sound have been accurately mcasmed and
counted Assuming the pitch OF the ordinary mas
culnc voice i'll conversation to be as low as hiddlc
G., the number of complete double vibrations I'M
parted by such voice 10 the telephone diaphragm
on tympanum would be $50 pei second that Is count
ing both WAYS 8 movements of the diaphragm y 18th
its metallic point making breaking the electrical
circuit at each movement. 10 the eye, winch
retains every impression for half second, 20O oil
these movements would make their impression AS
one, aud would give stationary, fictitious Huage,
if they of sufficient depth to produce any
visible effect whatever, as they are not: The elec-
trio spark, however, would give It's ILLUMINATION
md do ITS Photographic work within a little more
than one-ffticth of the time of one of the tym-
panum movements. A succession Of such photo
graphs, therefore, would present fOrtultOusIy any
position of the vibrating point from that Of contact
TO that of extreme TetractlOn with an indefinite
number of intermediate positions"
To verify these calculations Mr. lockwood care
fully focused his Photographic camera on the
points of the telephone by daylight, and battery
of Lcyden jars was 80 adjusted that when dis
charged it would throw the proper illumination OH
the points. Mr.. ROckwoods instantaneous plates
were now to be tested under action five hundred
times quicker than "A sensible instant and also IN
visibly minute. OF course it was ~ yet practical
question whether they could effectively receive as
quickly az the electric spark would give this III
fnitesimal action of light. Waiting until the
darkest hour of the night the plate uncovered
IN total darkness, the telephonist began speaking
into his instrument, and the illuminating spark was
flashed upon the points. This operation was re-
peatcd with more than twenty plates in succession
The resulting negatives, on being developed, prove
a triumph in two arts aud q science. The pho
tographs printed from them showed under The
glass, in some, contact of the points and IN others
variety of inhnitesmally diherenced Intervals be
tween them Not one Of the impressions had more
than the one twenty -four thousandth of second il
which to be begun and esded.
ENDING STRIKES AND LOCK-OUTS.
II IL probable that the strike of the cigar-maker
employed by JOsephs * Company, of East Sixty