By the law of nature our existence is divided between daylight and
darkness. There is evermore the alternate baptism into dawn and night.
The division of life is not perfect between sunshine and shadow; for
the sunshine bends around the world on both horizons, and lengthens
the hemisphere of day by a considerable rim of twilight. To this
reduction of the darkness we must add moonshine and starlight. But we
must also subtract the influence of the clouds and other incidental
conditions of obscuration. After these corrections are made, there is
for mankind a great band of deep night, wherein no man can work.
Whoever goes forth at some noon of night, when the sky is wrapped with
clouds, must realize the utter dependence of our kind upon the light.
How great is the blessing of that sublime and beautiful fact which the
blind Milton apostrophizes in the beginning of the Third Book of
_Paradise Lost_:
"Hail, holy Light! offspring of heaven first-born!
Or of Eternal coëternal beam,
May I express thee unblamed? since God is light,
And never but in unapproached light
Dwelt from eternity, dwelt then in thee,
Bright effluence of bright essence increate!
Or hear'st thou rather, pure ethereal stream,
Whose fountain who shall tell? Before the sun,
Before the heavens thou wert, and at the voice
Of God, as with a mantle, didst invest
The rising world of waters dark and deep,
Won from the void and formless infinite."
How then shall man overcome the darkness? It is one of the problems of
his existence. He is obliged with each recurring sunset of his life to
enter the tunnel of inky darkness and make his way through as best he
may to the morning. What kind of lantern shall he carry as he gropes?
The evolution of artificial light and of the means of producing it
constitutes one of the most interesting chapters in the history of our
race. Primeval man knew fire. He learned in some way how to kindle
fire. The lowest barbarian may be defined as a fire-producing animal.
The cave men of ancient Europe kindled fires in their dark caverns.
The lake dwellers had fires, both on shore and in their huts over the
water. Wherever there was a fire there was artificial light. The
primitive barbarian walked around the embers of his fire and saw his
shadow stretching out into the gloom of the surrounding night.
With the slow oncoming of a better estate, the early philosophers of
mankind invented lamps. Very rude indeed were the first products in
this kind of art. Note the character of the lamps that have survived
to us from the age of stone. Still they are capable of holding oil and
retaining a wick. Further on we have lamps from the age of bronze, and
at last from the age of iron. Polite antiquity had its silver lamps,
its copper lamps, and in a few instances its lamps of gold. The
palaces of kings were sometimes lighted from golden reservoirs of oil.
Such may be seen among the relics preserved to us from the
civilizations of Western Asia. The palace of Priam, if we mistake not,
had lamps of gold.
The Great Greeks were the makers of beautiful lamps. In the age of the
Grecian ascendancy the streets of Athens and of some other Hellenic
cities were lighted by night. The material of such illumination was
oil derived either from animals or from vegetable products, such as
the olive. In the forms of Greek lamps we have an example of artistic
beauty not surpassed or equaled in modern time; but the mechanical
contrivance for producing the light was poor and clumsy.
Rome lighted herself artificially. She had her lamps and her torches
and her chandeliers, as we see in the relics of Herculaneum and
Pompeii. A Roman procession by night was not wanting in brilliancy and
picturesqueness. The quality of the light, however was poor, and there
was always a cloud of smoke as well as of dust hovering about Roman
processions and triumphs.
The earlier Middle Ages improved not at all; but with the Renaissance
there was an added elegance in the apparatus of illumination.
Chandeliers were made in Italy, notably in Venice, that might rival in
their elegance anything of the present age. The art of such products
was superior; but the old barbaric clumsiness was perpetuated in the
mechanical part. With the rise of scientific investigation under the
influence of inductive philosophy, all kinds of contrivances for the
production of artificial light were improved. The ingenuity of man was
now turned to the mechanical part, and one invention followed another
with a constant development in the power of illumination.
We can but remember, however, that until the present age many of the
old forms of illuminating apparatus have been retained. In the ruder
communities such things may still be seen. Civilization in its
progress from east to west across our continent followed a tallow
candle. The light of it was seen by night through the window of the
pioneer's cabin. The old forms of hanging lamps have hardly yet
disappeared from the advance posts of the marching column. But
meanwhile, other agencies have been discovered, and other forms of
apparatus invented, until the branch of knowledge relating to
illumination has become both a science and an art.
Within the memories of men still living, a great transformation has
occurred. Animal oils have virtually ceased to be employed as the
sources of light. The vegetable world is hardly any longer drawn upon
for its products. Already before the discovery of petroleum and its
multifarious uses the invention by chemical methods of illuminating
materials had begun. Many kinds of burning fluid had been introduced.
The reign of these was short-lived; coal oil came in at the door and
they flew out at the window. Great was the advantage which seemed to
come to mankind from the use of kerosene lamps. Those very forms of
illumination which are now regarded as crude in character and odious
in use were only a generation ago hailed with delight because of their
superiority to the former agents of illumination. Thus much may
suffice for all that precedes the coming of the New Light of men. The
new light flashes from the electrical glow. The application of
electricity to purposes of illumination marks an era in human
progress. The electrical light is, we think, high up among the most
valuable and striking stages of civilized life in the nineteenth
century. It is best calculated to affect favorably the welfare of the
people, especially in great cities. The illumination of a city by
night, making its streets to be lighted as if by day, is a more
interesting and important fact in human history than any political
conflict or mere change of rulers.
About the beginning of the eighth decade of this century the project
of introducing the electric light for general purposes of illumination
began to be agitated. It was at once perceived that the advantages of
such lighting were as many as they were obvious. The light is so
powerful as to render practicable the performance of many mechanical
operations as easily by night as by day. Again, the danger of fire
from illuminating sources is almost wholly obviated by the new system.
The ease and expedition of all kinds of night employment are greatly
enhanced. A given amount of illumination can be produced much more
cheaply by electricity than by any means of gas lighting or ordinary
combustion. Among the first to demonstrate the feasibility of
electric lighting was the philosopher Gramme, of Paris. In the early
part of 1875 he successfully lighted his laboratory by means of
electricity. Soon afterward the foundry of Ducommun & Co., of
Mulhouse, was similarly lighted. In the course of the following year
the apparatus for lighting, by means of carbon candles was introduced
into many of the principal factories of France and other leading
countries of Europe. It may prove of interest in this connection to
sketch briefly the principal features of the electric light system,
and to trace the development of that system in our own and other
countries.
Lighting by electricity is accomplished in several ways. In general,
however, the principle by which the result is accomplished is one, and
depends upon the resistance which the electrical current meets in its
transmission through various substances. There are no perfect
conductors of electricity. In proportion as the non-conductive quality
is prevalent in a substance, especially in a metal, the resistance to
the passage of electricity is pronounced, and the consequent
disturbance among the molecular particles of the substance is great.
Whenever such resistance is encounted in a circuit, the electricity is
converted into heat, and when the resistance is great, the heat is, in
turn, converted into light, or rather the heat becomes phenomenal in
light; that is, the substance which offers the resistance glows with
the transformed energy of the impeded current. Upon this simple
principle all the apparatus for the production of electric light is
produced.
Among the metallic substances, the one best adapted by its low
conductivity to such resistance and transformation of force, is
platinum. The high degree of heat necessary to fuse this metal adds to
its usefulness and availability for the purpose indicated. When an
electrical current is forced along a platinum wire too small to
transmit the entire volume, it becomes at once heated--first to a red,
and then to a white glow--and is thus made to send forth a radiance
like that of the sun. Of the non-metallic elements which offer similar
resistance, the best is carbon. The infusibility of this substance
renders it greatly superior to platinum for purposes of the electric
light.
Near the beginning of the present century it was discovered by Sir
Humphry Davy that carbon points may be rendered incandescent by means
of a powerful electrical current. The discovery was fully developed in
the year 1809, while the philosopher just referred to was
experimenting with the great battery of the Royal Institution of
London. He observed--rather by accident than by design or previous
anticipation--that a strong volume of electricity passing between two
bits of wood charcoal produces tremendous heat, and a light like that
of the sun. It appears, however, that Davy at first regarded the
phenomenon rather in the nature of an interesting display of force
than as a suggestion of the possibility of turning night into day.
For nearly three-quarters of a century the discovery made by Sir
Humphrey lay dormant among the great mass of scientific facts revealed
in the laboratory. In the course of time, however, the nature of the
new fact began to be apprehended. The electric lamp in many forms was
proposed and tried. The scientists, Niardet, Wilde, Brush, Fuller, and
many others of less note, busied themselves with the work of
invention. Especially did Gramme and Siemens devote their scientific
genius to the work of turning to good account the knowledge now fully
possessed of the transformability of the electric current into light.
The experiments of the last named two distinguished inventors brought
us to the dawn of the new era in artificial lighting. The Russian
philosopher, Jablokhkoff, carried the work still further by the
practical introduction of the carbon candle. Other scientists--Carre,
Foucault, Serrin, Rapieff, and Werdermann--had, at an earlier or later
day, thrown much additional information into the common stock of
knowledge relative to the illuminating possibilities of electricity.
Finally, the accumulated materials of science fell into the hands of
that untutored but remarkably radical inventor, Thomas A. Edison, who
gave himself with the utmost zeal to the work of removing the
remaining difficulties in the problem.
Edison began his investigations in this line of invention in September
of 1878, and in December of the following year gave to the public his
first formal statement of results. After many experiments with
platinum, he abandoned that material in favor of the carbon-arc _in
vacuo_. The latter is, indeed, the essential feature of the Edison
light. A small semicircle, or horseshoe, of some substance, such as a
filament of bamboo reduced to the form of pure carbon, the two ends
being attached to the poles of the generating-machine, or dynamo, as
the engine is popularly called, is enclosed in a glass bulb, from
which the air has been carefully drawn, and is rendered incandescent
by the passage of an electric current. The other important features of
Edison's discovery relate to the divisibility of the current, and its
control and regulation in volume by the operator. These matters were
fully mastered in the Edison invention, and the apparatus rendered as
completely subject to management as are the other varieties of
illuminating agencies.
It were vain to speculate upon the future of electric lighting. The
question of artificial illumination has had much to do with the
progress of the human race, particularly when aggregated into cities.
Doubtless the old systems of lighting are destined in time to give
place altogether to the splendors of the electric glow. The general
effect of the change upon society must be as marked as it is salutary.
Darkness, the enemy of good government and morality in great cities,
will, in great measure, be dispelled by the beneficent agent, over
which the genius of Davy, Gramme, Brush, Edison, and a host of other
explorers in the new continents of science has so completely
triumphed. The ease, happiness, comfort, and welfare of mankind must
be vastly multiplied, and the future must be reminded, in the glow
that dispels the night, of that splendid fact that the progress of
civilization depends, in a large measure, upon a knowledge of Nature's
laws, and the diffusion of that knowledge among the people.