HF The History of Photography 600pág

The photography of movement 43 5
Janssen, as well as Pollock, foresaw the possibility of rapidly recording with such
an instrument a whole cycle of movements of animals and birds for the purpose of
solving problems of physiological mechanism, provided faster plates were invented.5
His suggestion did not pass unheeded, for after the introduction of gelatine plates
DR ETIENNE JULES MAREY reverted to Janssen's type of camera for recording the Pl 245
movement of birds in flight. Marey, who had studied medicine to please his father,
was professor of medicine at the University of Paris, but a life-long preference for
mechanical science led him to the invention of a great many physiological recording
instruments. From researches on the circulation of the blood he turned to the investigation
of muscular movement, eventually devoting himself entirely to the study
of movement of animals and insects, on the earth, in the water, and in the air (a subject
which had engaged the attention of physiologists since the middle of the seventeenth
century), and in 1869 he was appointed professor of natural history at the
College de France.
Marey's chronography. Marey devised various apparatus for recording chronographically
the consecutive movements of animal locomotion. To determine the gait
of horses, for instance, he fitted a rubber ball in each hoof, with a tube leading to a
revolving cylinder with paper wound round it, which was held by the rider. When
the pressure of the horse's hooves compressed the rubber balls, air was forced up the
tubes, and caused four tracing needles to record the length of contact of each hoof
with the ground. The notations were transcribed by Colonel Duhosset into drawings
of the horse in motion, which appeared animated when exhibited in the zoetrope. 6
Muybridge' s photographs of the horse in motion. Some improbable-looking attitudes
of the horse, which were published in one of Marey' s articles, led to a dispute between
Leland Stanford, ex-Governor of California, and his friend Frederick MacCrellish,
both great horse-lovers. As the latter could not believe that a fast trotting horse ever
has all its feet off the ground at the same time, it occurred to Stanford to call in
EADWEARD MUYBRIDGE7 -who was engaged at the time in making a photographic
survey of the Pacific Coast for the U.S. Government-to settle the controversy by
photography. However, the photographs which Muybridge took in May I 872 at the
race-course at Sacramento were inconclusive, according to the official account8
(because he lacked a quick-acting shutter), but Muybridge claimed that one of his
photographs did prove that Stanford was right.
Some time after these experiments Muybridge had to leave the United States after
killing his wife's lover. On returning to San Francisco in 1877, he resumed his investigations
of the horse's gait at Stanford's stud farm, Palo Alto. His first subject was
Stanford's racing trotter 'Occident', whose dark colour showed up well against a
white screen, in front of which the horse passed at a speed of 22± miles an hour, and
at a distance of approximately 40 ft from the camera. Though the negatives were
necessarily under-exposed, being taken in -rdoo second, one of the resulting silhouette
pictures showed the horse with all its hooves clear of the ground, thus settling the old
controversy at last.
The success of this experiment encouraged Stanford to have it repeated on an
extended scale by increasing the number of cameras and arranging them in a row
parallel to the running track, with the object of obtaining at short regular intervals
of time or distance several consecutive phases of the horse's movement during a single
complete stride. This method of recording movement was not so original as it might
seem. In 1860 THOMAS ROSE, an amateur photographer, suggested using 100 stereoscopic
cameras in a row, giving exposures of i second at intervals of the same duration.
The positive prints were to be mounted in pairs on a large phenakistiscope disk,