the right instant, a series of very
clear instantaneous photographs was obtained. From these negatives,
when developed, positive prints were made, which were later mounted on a
modified form of Zoetrope and projected upon a screen.

One of these early exhibitions is described in the Scientific American
of June 5, 1880: "While the separate photographs had shown the
successive positions of a trotting or running horse in making a single
stride, the Zoogyroscope threw upon the screen apparently the living
animal. Nothing was wanting but the clatter of hoofs upon the turf, and
an occasional breath of steam from the nostrils, to make the spectator
believe that he had before him genuine flesh-and-blood steeds. In the
views of hurdle-leaping, the simulation was still more admirable, even
to the motion of the tail as the animal gathered for the jump, the
raising of his head, all were there. Views of an ox trotting, a wild
bull on the charge, greyhounds and deer running and birds flying in
mid-air were shown, also athletes in various positions." It must not be
assumed from this statement that even as late as the work of Muybridge
anything like a true illusion of movement had been obtained, because
such was not the case. Muybridge secured only one cycle of movement,
because a separate camera had to be used for each photograph and
consequently each cycle was reproduced over and over again. To have made
photographs of a trotting-horse for one minute at the moderate rate of
twelve per second would have required, under the Muybridge scheme, seven
hundred and twenty separate cameras, whereas with the modern art only a
single camera is used. A further defect with the Muybridge pictures was
that since each photograph was secured when the moving object was in the
centre of the plate, the reproduction showed the object always centrally
on the screen with its arms or legs in violent movement, but not making
any progress, and with the scenery rushing wildly across the field of
view!

In the early 80's the dry plate was first introduced into general
use, and from that time onward its rapidity and quality were gradually
improved; so much so that after 1882 Prof. E. J. Marey, of the French
Academy, who in 1874 had published a well-known treatise on "Animal
Movement," was able by the use of dry plates to carry forward the
experiments of Muybridge on a greatly refined scale. Marey was, however,
handicapped by reason of the fact that glass plates