Artificial Light | Page 4

light ranks high. As an influence upon
civilization, no single achievement surpasses it.
Without artificial light, mankind would be comparatively inactive
about one half its lifetime. To-day it has been fairly well established
that the human organism can flourish on eight hours' sleep in a period
of twenty-four hours. Another eight hours spent in work should settle
man's obligation to the world. The remaining hours should be his own.
Artificial light has made such a distribution of time possible. The
working-periods in many cases may be arranged in the interests of
economy, which often means continuous operations. The sun need not
be considered when these operations are confined to interiors or
localized outdoors.
Thus, artificial light has been an important factor in the great industrial

development of the present time. Man now burrows into the earth,
navigates under water, travels upon the surface of land and sea, and
soars among the clouds piloted by light of his own making. Progress
does not halt at sunset but continues twenty-four hours each day.
Building, printing, manufacturing, commerce, and other activities are
prosecuted continuously, the working-shifts changing at certain periods
regardless of the rising or setting sun. Adequate artificial lighting
decreases spoilage, increases production, and is a powerful factor in the
prevention of industrial accidents.
It has ever been true since the advent of artificial light that the intellect
has been largely nourished after the completion of the day's work. The
highly developed artificial lighting of the present time may account for
much of the vast industry of publication. Books, magazines, and
newspapers owe much to convenient and inexpensive artificial light,
for without it fewer hours would be available for recreation and
advancement through reading. Schools, libraries, and art museums may
be attended at night for the betterment of the human race. The immortal
Lincoln, it is said, gained his early education largely by the light of the
fireplace. But all were not endowed with the persistence of Lincoln, so
that illiteracy was more common in his day than in the present age of
adequate illumination.
The theatrical stage not only depends for its effectiveness upon
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 reasonable to expect
that after many centuries of cultivation of the appreciation of
light-symphonies, these will take a place among the arts. The elaborate
and complicated music of the present time is appreciated by civilized
nations only after many centuries of slow cultivation of taste and
understanding.
Light-therapy is to-day a distinct science and art. The germicidal action
of light-rays and of some of the invisible rays which ordinarily
accompany the luminous rays is well proved. Wounds are treated
effectively and water is sterilized by the ultraviolet radiant energy in
modern artificial illuminants.
Thousands of lighthouses, light-ships, and light-buoys are scattered
along sea-coasts, rivers, and channels. They guide the wheelman and
warn the lookout of shoals and reefs. Some of these send forth flashes
of light whose intensities are measured in millions of candle-power.
Many are unattended for days and even months. These powerful lights
dominated by automatic mechanisms have replaced the wood-fires
which were maintained a