THE MOTION PICTURES AS AN AID TO SCIENTIFIC INVESTIGATION
Rapid strides are being made in the utilisation of animated photography
as an aid to scientific investigation. It is a development useful in
all fields of research where phenomena can be recorded in pictorial
form. Dr. E. J. Marey, the eminent French scientist, was the pioneer
in this work. One has only to peruse his classic work "Movement"[4]
to realise the comprehensive nature of his studies. So thoroughly did
he cover the ground of chronophotography, as it was then called, that
it is difficult to conceive where any new application of the motion
picture can now be made.
[4] "Movement," by E. J. Marey. Heinemann, 7_s._ 6_d._
The Aurora Borealis always has been a subject fascinating to
scientists. Numerous papers and brochures have been written about it,
and many elaborate drawings have been prepared to convey some idea
of its characteristics and its kaleidoscopic changes. The drawings,
however, fail to convince, and even the few still-life photographs
which have been taken are uneventful.
Realising this deficiency a Danish professor is striving to record the
Aurora Borealis in motion upon the celluloid film. A special camera
has been designed for his work, and with this it is intended to snap
the phenomena from a convenient northern point such as Spitzbergen or
Greenland, not only for the benefit of the scientific world but also
for the general public which entertains only a hazy conception of the
"Northern Lights." It need hardly be said that if this investigator
should succeed in his difficult quest he will reveal upon the screen
one of the most extraordinary wonders of the world. While the
marvellous and weird colouring effects will be missing, the curtains of
light that drape the sky, and the strange luminous shafts and glares
which light the heavens, should provide a film of intense interest and
fascination.
The moving-picture camera is also being applied to the recording of
solar eclipses with a view to obtaining a more impressionistic and
intimate idea of the activity and extent of the flames which shoot from
the surface of the sun. Wonderful still-life pictures of these effects
have been taken, and it is only fair to assume that they should be
capable of being caught by the motion-picture camera. Efforts are also
being made to secure photographs of the heavens, but the difficulties
are very great. The long exposure required in this case is a heavy
drawback, but seeing that the slowest movements of Nature can be
recorded by the cinematograph, and may be speeded up in projection to
convey the effect of animation, there is no reason why similar moving
pictures of other worlds should not be obtained by combining the
moving-picture camera with the telescope. The moon followed through its
phases would yield an interesting study, and, incidentally, a film of
this character would possess considerable educational value.
At the present moment great activity is being manifested in the
application of the cinematograph to mechanics. Two Sheffield
investigators have designed a steel-testing machine to which is
attached a microscope and a cinematograph camera. The piece of steel
to be tested is placed in the machine and the cinematograph is set
in motion. By throwing the resulting pictures upon the screen it
is possible to follow exactly what takes place in the molecular
construction of the steel while it is under test.
The idea has been applied to many other phases of mechanics with equal
success, and there have been many discoveries of a technical nature
which have had their effect upon manufacturing processes.
Another series of technical experiments was carried out by Dr. Otto
Füchs, professor of engineering at the German Technical High School of
Brünn. The purpose was to elucidate some hitherto obscure points in
connection with the working of steam hammers. Investigations in this
field have hitherto proceeded on the graphic principle, the results
being recorded by a stylo continually travelling over calibrated paper.
It is admitted that this system leaves much to be desired because the
stylo is not sufficiently sensitive, and fails to record many of the
smaller and more important movements. Accordingly, Dr. Füchs conceived
the idea of using the moving-picture camera in the anticipation that
much missing data might thus be discovered.
A special apparatus was designed. In reality it is an ingenious
combination of the moving-picture camera and the graphic method. There
is a paper tape that passes continuously over two rollers and has two
stylos constantly bearing on it. These stylos are connected with two
indicators attached to the sides of the cylinder of the steam hammer,
and they supply a continuous record of the steam pressure. The paper
tape is moved by an electrically-driven gear, while time intervals are
indicated by means of clockwork mechanism. So much for the graphic
portion.
[Illustration:
_By courteous permission of Dr. Otto Füchs._
MOVING-PICTURES OF A STEAM HAMMER RAM.
An illuminated index attached to the ram moves over a graduated scale,
while an illuminated clock indicates the lapse of time.]
[Illustration: DR. OTTO FÜCHS' APPARATUS FOR TAKING MOVING-PICTURES
OF THE OPERATIONS OF A STEAM HAMMER.]
What the cinematographic portion supplies is a continuous animated
record of the movement of the ram of the hammer. Attached to the ram is
an index which moves up and down over a scale divided into centimetres.
Both the index and the scale are illuminated so that the result given
by the camera shows a series of photographic images of the oscillating
motion. Above the illuminated finger and scale is a clock similar to
Marey's chronoscope and Gilbreth's timepiece, driven by clockwork, and
in synchrony with the remainder of the mechanism. This scale likewise
has its points of division illuminated. Its use is to supply the time
factor without which such experiments are useless.
The ram, the index-finger, the scale and the clock are all recorded
upon the film, so that it is possible to tell the varying speeds at
which the ram moves throughout its travel. The photographing speed may
be varied as desired, and as a different position is caught in each
picture, the distance the ram travels between two successive exposures,
together with the time occupied in completing the cycle of movement,
may be accurately gauged. The combination of the paper tape recorder
with the photographic part of the apparatus affords a complete record
of the ram's performance.
The results are naturally of a severely technical character and of
interest only to persons concerned with mechanics. But to these they
are very important indeed. The experiments which have been completed by
Dr. Füchs have thrown much light upon a difficult engineering problem.
They have served to answer questions affecting the design of the hammer
and its most economical efficient operation which would otherwise
have been insoluble. From the public point of view the films possess
no interest whatever, inasmuch as the subject is illuminated and
photographed in such a way that only the features of technical interest
are brought out strongly upon the film.
Another interesting and profitable province of the cinematograph is
that concerning ballistics. This has been worked out by Monsieur Lucien
Bull at the Marey Institute with his camera capable of taking two
thousand pictures per second under the illumination of the electric
spark. While this investigator did not apply his invention directly
to ballistics he indicated the manner in which such work could be
carried out. The success of his experiments, however, prompted another
investigator to enter the field. This was Dr. Cranz, of the Berlin
Military Academy. The apparatus this professor evolved has been
devoted exclusively to the study of the flight of projectiles and to
photographing the action of the mechanism of the magazine type of
firearm.
[Illustration:
_By courtesy of the Marey Institute._
THE WONDERFUL APPARATUS DEVISED BY MR. LUCIEN BULL FOR TAKING 2,000
PICTURES PER SECOND.
Showing stereoscopic camera, interrupter, condenser, coil, and
resistance. Illumination is obtained by the electric spark.]
[Illustration:
(1) (2)
FILMS PREPARED BY PROFESSOR CRANZ WITH HIS REMARKABLE CAMERA.
(1) Moving-pictures of the ejection of a cartridge from an automatic
pistol.
(2) Motion photographs of the splintering of a bone by a bullet.]
The Cranz apparatus is somewhat more complicated than that designed
by Monsieur Bull, though the fundamental principle of operation is
the same. The film, resembling an endless belt, is passed round two
steel cylinders, one of which is driven by an electric motor. Images
of standard size are produced under the illumination of the electric
spark, which concentrates the maximum amount of light upon the moving
object. The photograph is in silhouette, and the disposition of the
apparatus is such that five hundred consecutive pictures can be made
in one-tenth of a second, the period of exposure varying between
one-millionth and one-ten-millionth of a second. The outstanding
feature of the installation is the special and novel type of
interrupter. It consists of a pendulum by which the sparking is started
before the projectile is fired and made to continue until the film has
been exhausted.
Some of the results obtained by this apparatus are very remarkable.
When the films are projected upon the screen at the average speed of
sixteen pictures per second the flight of the bullet can be followed
with ease. One film shows the effect of a bullet striking a suspended
india-rubber ball filled with water, and brings out the remarkable
formations the ball assumes during the infinitesimal part of a second
when the bullet is passing through it. Another interesting film shows
the effect of a high velocity bullet striking a bone, and the manner
in which the bone is splintered and smashed by the force of the impact
conveys a realistic impression of the destructive force of the modern
rifle projectile. The deadliness of the automatic pistol is well known.
Since seven shots may be discharged in four seconds, the movements of
the mechanism are too rapid to be followed by the naked eye. Yet by
means of the Cranz apparatus every motion is caught, and the whole is
slowed down in projection to such a degree that the complete cycle
of the firing of the shot and the expulsion of the cartridge, which
normally occupies only a fraction of a second to complete, occupies
about thirty seconds upon the screen. When these pictures were
exhibited for the first time a number of black specks were observed
to accompany the expulsion of the spent cartridge. These proved to
be grains of powder which had not been ignited. Their existence had
never before been suspected, and the result was curious. After minute
examination of the pictures a change was effected in manufacture of
the cartridge so that the waste of powder through non-ignition should
be reduced to the minimum. The success achieved in this direction was
shown by the absence of non-ignited grains in subsequent pictures.
Another wonderful series of moving pictures was prepared by an
American ophthalmic surgeon. He embarked upon elaborate researches
to gain further information about the eye and its peculiarities both
in sickness and in health. The illumination of the eye was carried
out very cleverly, so as to obtain the greatest possible brilliancy
without causing fatigue to the subject. Accordingly his pictures were
absolutely normal. In these experiments glass plates were used, for
the reason that they give results much finer and more detailed than
celluloid. In celluloid the grain of the base of the film is apt to
be disturbing to very fine studies. In this way a great deal of new
information was gained. One of the most remarkable discoveries was
that the sensitiveness of the organ of sight is far greater than was
previously supposed, and that the eye never is absolutely still, even
when commonly regarded as being fixed and steady.
During the past two or three years the uses of the cinematograph in
medicine have been much extended. A former chapter has described its
application to the study of microbic life, but the latest innovation is
to employ it in the operating room. The pages of the medical papers
are filled with reports of curious and unusual surgical operations,
but mere reports are necessarily somewhat imperfect. In view of these
circumstances it occurred to one eminent surgeon that a cinematographic
record would form a first-class supplement to the technical
description. The initial experiment proved a complete success, and
accordingly the practice has been extended. In this direction France,
Germany, and the United States are taking a very active part. Films
of this character can be made to serve two useful purposes. They are
valuable for the transmission of practical information between medical
men and are useful in the lecture room among the students. Suppose a
hospital in New York has a strange and unusual case for operation. Only
the students in that establishment have the opportunity of witnessing
it. But by the aid of the moving-picture camera and a lecture it can be
reproduced in photographic animation upon the screen for the benefit of
medical graduates in the various hospitals throughout the world.
In research work, such as the study of new and unusual diseases,
especially those of a tropical nature, it is possible to obtain a
continuous record of a subject from the moment of infection through the
various stages of the malady. For instance, in the study of sleeping
sickness in Uganda, Colonel Bruce had formerly to content himself with
a graphic record or chart of the fluctuations of a patient's condition,
with explanatory notes introduced here and there when a sudden change
in the temperature or general behaviour of the patient developed.
With the cinematograph it is possible to obtain a pictorial record
which conveys a more forceful and exact impression of the symptoms.
An interesting indication of what could be done in this direction was
the film prepared by Dr. Comandon. He used a monkey for his subject,
infecting it with the microbe of sleeping sickness discovered by
Colonel Bruce. The effects which the bacteria produced upon the monkey
were admirably illustrated, together with the changes that various
remedies wrought in its condition.
So far as concerns the application of the cinematograph to scientific
research the greatest strides have been made in physiology. This
was due to Marey's enthusiasm in this branch of science, and the
establishment of the Physiological Institute in Paris where such
investigations were carried out upon a most exhaustive scale. The
results of Marey's investigations are given in several volumes
and in hundreds of papers which he sent to the various French
scientific societies. There is no reason why the contributions of
the cinematograph to physiological knowledge should not be equalled
in other branches of science. Up to the present the investigation of
scientific phenomena with the aid of motion-pictures has not been
carried far, but there are many signs that its sphere will be extended
in the future.