artificial light but owes its existence and development largely to this
agency. In the moving-picture theater, pictures are projected upon the
screen by means of it and even the production of the pictures is
independent of daylight. These and a vast number of recreational
activities owe much, and in some cases their existence, to artificial
light.

Not many centuries ago the streets at night were overrun by thieves and
to venture outdoors after dark was to court robbery and even bodily
harm. In these days of comparative safety it is difficult to realize the
influence that abundant illumination has had in increasing the safety of
life and property. Maeterlinck in his poetical drama, "The Bluebird,"
appropriately has made _Light_ the faithful companion of mankind. The
Palace of Night, into which _Light_ is not permitted to enter, is the
abode of many evils. Thus the poet has played upon the primitive
instincts of the impressiveness of light and darkness.

By combining the symbolism of light, color, and darkness with the
instincts which have been inherited by mankind from its superstitious
ancestry of the age of mythology, another field of application of
artificial light is opened. Light has gradually assumed such attributes
as truth, knowledge, progress, enlightenment. Throughout the early ages
light was more or less worshiped and thus artificial lights became woven
in many religious ceremonies. Some of these have persisted to the
present time. The great pageants of peace celebrations and world's
expositions appropriately feature artificial light. In drawing upon the
potentiality of the expressiveness and impressiveness of light and
color, artificial light is playing a major part. Doubtless the future
generations will be entertained by gorgeous symphonies of light.
Experiments are performed in this direction now and then, and it is