accomplishment, and
in fact before the production of a suitable generator for delivering
electric current in a satisfactory and economical manner.

It is a curious fact that while the modern art of motion pictures
depends essentially on the development of instantaneous photography,
the suggestion of the possibility of securing a reproduction of animate
motion, as well as, in a general way, of the mechanism for accomplishing
the result, was made many years before the instantaneous photograph
became possible. While the first motion picture was not actually
produced until the summer of 1889, its real birth was almost a century
earlier, when Plateau, in France, constructed an optical toy, to which
the impressive name of "Phenakistoscope" was applied, for producing an
illusion of motion. This toy in turn was the forerunner of the Zoetrope,
or so-called "Wheel of Life," which was introduced into this country
about the year 1845. These devices were essentially toys, depending for
their successful operation (as is the case with motion pictures) upon
a physiological phenomenon known as persistence of vision. If, for
instance, a bright light is moved rapidly in front of the eye in a dark
room, it appears not as an illuminated spark, but as a line of fire;
a so-called shooting star, or a flash of lightning produces the same
effect. This result is purely physiological, and is due to the fact
that the retina of the eye may be considered as practically a sensitized
plate of relatively slow speed, and an image impressed upon it remains,
before being effaced, for a period of from one-tenth to one-seventh of
a second, varying according to the idiosyncrasies of the individual and
the intensity of the light. When, therefore, it is said that we should
only believe things we actually see, we ought to remember that in almost
every instance we never see things as they are.

Bearing in mind the fact that when an image is impressed on the human
retina it persists for an appreciable period, varying as stated,
with the individual, and depending also upon the intensity of the
illumination, it will be seen that, if a number of pictures or
photographs are successively presented to the eye, they will appear as
a single, continuous photograph, provided the periods between them are
short enough to prevent one of the photographs from being effaced before
its successor is presented. If, for instance, a series of identical
portraits were rapidly present