—_——— 
May 30, 1912]| ¢ 
GAUMONT. SPEAKING KINEMATO- 
GRAPH FILMS.+ 
OHANNES MULIER, one of the greatest physio- 
logists of last century, when considering the time 
factor in nervous processes, was so impressed with 
the inherent difficulties of the question, that he said, 
“We shall probably never attain the power of measur- 
ing the velocity of nervous action, for we have no 
opportunity of comparing its propagation through 
immense space as we have in the case of light.’’ As 
is often the case, when the forecast is darkest light is 
near. As it has in the case of determining the velocity 
of a nervous impulse by Helmholtz, so it has in the 
synchronisation of the kinematograph and phono- 
graph. The question of synchronisation of a camera 
and a talking machine is a problem that attracted 
the attention of Edison himself from the time of his 
invention of the kinetoscope, an instrument, how- 
ever, in which only one person at a time could see 
the moving picture. 
It is not enough to have a perfect synchronism 
between the phonograph and the kinematograph— 
between the talking machine and the camera. The 
vocal sounds of one or more speakers must be regis- 
tered at a distance of several yards from the phono- 
graph. To do this without altering the purity and 
intensity of the sounds emitted is no easy problem. 
Obviously the phonograph and kinematograph 
must be placed in the same electrical circuit. Experi- 
ence has shown that the phonograph must control the 
action of both instruments. In July, tgo01, the 
Gaumont Company obtained the first patent for such 
an arrangement, 
The problem is how to obtain at the same time 
records from a kinematograph and from a phono- 
graph, gramophone, or talking machine, and, having 
obtained these, how can they be reproduced and pre- 
sented simultaneously, the one record to the eye and 
the other to the ear, so that a large audience—even 
six thousand in number—shall be able to see and hear 
that all marches in unison and produces an illusion 
so complete as almost to represent real life. 
In the ordinary speaking and moving pictures 
which have been. presented hitherto, the actor or 
singer has just to speak or sing into a phonograph 
placed close to his mouth, whereby a record is 
obtained. This is reproduced on an _ appropriate 
machine, and when he hears the sounds he makes as 
best he can the appropriate sounds, movements, and 
gestures while the kinematograph records. There is 
no question of simultaneous recording and reproduc- 
tion of the double record. Consequently, the result is 
not satisfactory. By means of the combination of a 
THE 
NATURE 
222 
III 
correlation between the movements of the speakers, 
or actors, or singers, and the audible sounds as re- 
gards pitch, loudness, and quality of the vocal or 
other sounds. 
It has been calculated that in a record on an 
ordinary 12-in. disc of a gramophone the length of 
its sinusoidal sound line or spiral groove—counting 
roo grooves to the inch from the centre to the circum- 
ference of the disc—is about 240 yards, or 720 ft. If, 
however, the ripples made by the vibrating stylus 
as the disc revolves under it at the rate of 32 in. per 
second be added, it brings up the total length of the 
sound line—in the reproduction of a sound record 
lasting from three to four minutes—to, it may be, 
500 yards, or 1500 ft. The disc makes about 76 
revolutions per minute, or an average rate of each 
revolution in o-8 second. 
In order to produce what M. Gaumont has called 
“filmparlants,’’ or speaking kinematograph films, two 
motors of identical pattern actuated from the same 
source, and of approximately the same power, are 
used for driving the phonograph and the kinemato- 
graph. A rheostat introduced into the circuit enables 
the operator to vary at will the velocity of the motors, 
even when they are in action. 
Experience has shown that the best results are 
obtained by first setting in action the dynamos and 
the phonograph. The kinematograph is not engaged 
until a given moment. This can be arranged by 
placing a clutch between the kinematograph and its 
motor. The automatic engagement apparatus is con- 
trolled by a lever connected with the armature of an 
electromagnet, which is actuated at a given moment 
which corresponds with a definitely determined posi- 
tion of the needle in one of the grooves of the disc 
of the phonograph, which is of the gramophone type. 
If, however, by any chance there is a discord, how- 
ever small, even a fraction of a second, between the 
emission of the sound by the talking machine and the 
movement of the lips of the speaker, there is a special 
arrangement, called the “differential,” by means of 
which any want of accord between the phonograph 
and camera can be immediately rectified. The differ- 
ential gearing, which is placed on the shaft between 
the kinematograph and its motor, and is actuated by 
means of a special small motor, is provided with a 
reversing commutator which enables the operator to 
control the speed of the kinematograph, either hasten- 
ing or slowing its movements. The speed of the 
phonograph remains constant, so that all correction 
in speed, in order to synchronise the two machines, 
| is done by accelerating or retarding the speed of pro- 
| jection by means of the kinematograph. By means” 
camera, a talking machine, and a megaphone, the | 
combination being termed by M. Gaumont the 
chronophone, large scenes as well as the effects of a 
full chorus are obtained at one and the same 
operation. 
At first sight it might seem as if the problem of 
producing simultaneously combined pictorial and 
audible records was a comparatively simple one. It 
is, however, far from being so. We may lay down 
the following conditions :— 
(1) Absolute synchronism between the phonograph 
and the kinematograph both in recording and repro- 
ducing the result. 
(2) Registration of sound by the phonograph at a 
of the differential any accidental displacement of the 
phonograph needle during the projection can instantly 
_ be rectified. 
sufficient distance at the same time as the registration | 
of the pictures on the moving film, without the phono- 
graph being in the field of the kinematograph. 
(3) The amplification of the sound so that a large 
audience can hear the sound and observe the exact 
1 Abstract of a discourse delivered at the Royal Institution on Friday, 
May 10, by Prof. William Stirling. 
NO. 2222, VOL. 89] 
In order that the operator may be in close proximity 
to the phonograph, and to enable him to make sure 
that everything works well and to regulate the 
apparatus, he has before him a rectangular box called 
‘““Chef d’Orchestre,” but which is practically a “con- 
trol board,” fitted with a voltmeter which acts as a 
speed indicator, a frequency meter which gives 
exactly the angular velocity at each instant of the 
phonograph, a starting gear with a series of resist- 
ances, whereby the phonograph is set in motion, and 
a two-way commutator in connection with the differ- 
ential motor. 
The following coloured speaking films, amongst 
others, were demonstrated by means of the “chrono- 
phone” by way of showing its applicability to the 
reproduction of all kinds of vocal sounds 0) A 
Gallic cock placed on a pedestal, where he crows right 
lustily, so that the whole audience could hear the 
