y as a light-source can
be determined. Its efficiency as a lighting-plant may be and perhaps is
rather low.

VIII

MODERN GAS-LIGHTING

As has been seen, the lighting industry, as a public service, was born
in London about a century ago and companies to serve the public were
organized on the Continent shortly after. From this early beginning
gas-light remained for a long time the only illuminant supplied by a
public-service company. It has been seen that throughout the ages little
advance was made in lighting until oil-lamps were improved by Argand in
the eighteenth century. Candles and open-flame oil-lamps were in use
when the Pyramids were built and these were common until the approach of
the nineteenth century. In fact, several decades passed after the first
gas-lighting was installed before this form of lighting began to
displace the improved oil-lamps and candles. It was not until about 1850
that it began to invade the homes of the middle and poorer classes.
During the first half of the nineteenth century the total light in an
average home was less than is now obtained from a single light-source
used in residences; still, the total cost of lighting a residence has
decreased considerably. If the social and industrial activities of
mankind are visualized for these various periods in parallel with the
development of artificial lighting, a close relation is evident. Did
artificial light advance merely hand in hand with science, invention,
commerce, and industry, or did it illuminate the pathway?

Although gas-lighting was born in England it soon began to receive
attention elsewhere. In 1815 the first attempt to provide a gas-works in
America was made in Philadelphia; but progress was slow, with the result
that Baltimore and New York led in the erection of gas-works. There are
on record many protests against proposals which meant progress in
lighting. These are amusing now, but they indicate the inertia of the
people in such matters. When Bollman was projecting a plan for lighting
Philadelphia by means of piped gas, a group of prominent citizens
submitted a protest in 1833 which aimed to show that the consequences of
the use of gas were appalling. But this protest failed and in 1835 a
gas-plant was founded in Philadelphia. Thus gas-lighting, which to Sir
Walter Scott was a "pestilential innovation" projected by a madman,
weathered its early difficulties and grew to be a mighty industry.
Continued improvemen