AN HISTORICAL STUDY 451 
picture. Any well-informed engineer, trying to forecast the course of 
invention in 1920, might have foretold that the sound film would come ; 
but he would probably not have guessed that photoelectric cells would play 
any part in it ; he would probably have looked to the gramophone to provide 
the sound. 
However, there was another possibility in the oft-invented and oft- 
forgotten photophone. That you will remember is an instrument for con- 
verting variations of light into sound by means of photoelectric cells. If it 
were to be used for this purpose, the sound to be reproduced had to be 
recorded in the form of potential variations of light. Now this problem 
had actually been studied in the early days of the photophone ; methods had 
been devised for recording the vibrations of sound in the form of cyclical 
variations of density in a photographic plate, so that when the plate was 
passed across a beam of light, the light would vary in accordance with the 
sound vibrations. We will not stop to explain how this is done ; there are 
several methods ; and the remarkable thing is that all of them were invented 
in principle round about 1880. But they were greatly developed in the 
first ten years of this century for the purpose of studying sound. Accord- 
ingly methods of recording sound in a form from which it might be repro- 
duced by the photophone were already available. 
By the early twenties several people had seen that here was an alternative 
to the gramophone for associating sound with the talking picture. Perhaps 
the most energetic was de Forest, whose name will always be associated 
with the audion, the first thermionic amplifier. By 1923 he had really 
succeeded in printing on the same film with a moving picture a sound 
record which produced recognisable sounds; but the reproduction was 
definitely not as good as that of the contemporary gramophone. 
So it was not lack of technical development which delayed so long the 
coming of the sound film, or any great technical advance that finally pro- 
duced it. It was—to speak frankly—the artistic ineptitude of the magnates 
of Hollywood. The cinema was past its first youth. Its technique had 
lost its wonder even for the half-civilised races, and more sophisticated 
patrons were grumbling at the poverty of imagination displayed by those 
who controlled so wonderful an instrument. Hollywood saw that some- 
thing had to be done to stimulate a flagging demand ; they decided to appeal 
to the lower rather than to the higher instinct of mankind, to drown criticism 
in the clamorous excitement of a new ‘ stunt’ rather than to satisfy it by a 
belated appeal to intelligence. They would introduce a yet cruder realism ; 
they would reunite sound and sight which the cinema had divorced. The 
public should have the thrill of talking pictures ! 
They began with gramophone records—sound-on-disc, as it is called. 
And if technical excellence had been the sole consideration, they might long 
have kept to them. It is only quite recently that the alternative sound-on- 
film has equalled and even surpassed the best gramophone record. We 
must insist on that, because those who do not like sound films must not 
blame photoelectric cells for their deficiencies. If you think they are 
worse than silent films—for this is the only question—if you think that the 
art of Walt Disney is a poor substitute for that of Charlie Chaplin, you must 
remember that the change might have and probably would have occurred, 
if photoelectricity had never been heard of. Perhaps we might not have 
had the ‘ Home Talkies ’ with which we are now threatened ; but public 
talkies we should have certainly had. That is important, because we are 
apt to forget when we are discussing history that the same effect may arise 
from quite different causes, and that abolishing the immediate cause does 
not always mean abolishing the actual effect. 
