n light by heating a
mantle of fine platinum gauze. Although these mantles emitted a
brilliant light for a few hours, their light-emissivity was destroyed by
carbonization. After the appearance of the Welsbach mantle, Kitson's
lamp and others met with success by utilizing it. From this point,
attention was centered upon the new wonder, which is discussed in a
later chapter after certain scientific principles in light-production
have been discussed.

The kerosene or mineral-oil lamp was a boon to lighting in the
nineteenth century and even to-day it is a blessing in many homes,
especially in villages, in the country, and in the remote districts of
civilization. Its extensive use at the present time is shown by the fact
that about eight million lamp-chimneys are now being manufactured yearly
in this country. It is convenient and safe when carelessness is avoided,
and is fairly free from odor. Its vitiation of the atmosphere may be
counteracted by proper ventilation and there remains only the
disadvantage of keeping it in order and of accidental breakage and
overturning. The kerosene lantern is widely used to-day, but the danger
due to accident is ever-present. The consequences of such accidents are
often serious and are exemplified in the terrible conflagration in
Chicago in 1871, when Mrs. O'Leary's cow kicked over a lantern and
started a fire which burned the city. Modern developments in lighting
are gradually encroaching upon the territory in which the oil-lamp has
reigned supreme for many years. Acetylene plants were introduced to a
considerable extent some time ago and to-day the self-contained
home-lighting electric plant is being installed in large numbers in the
country homes of the land.

VI

EARLY GAS-LIGHTING

Owing to the fact that the smoky, flickering oil-lamp persisted
throughout the centuries and until the magic touch of Argand in the
latter part of the eighteenth century transformed it into a commendable
light-source, the reader is prepared to suppose that gas-lighting is of
recent origin. Apparently William Murdock in England was the first to
install pipes for the conveyance of gas for lighting purposes. In an
article in the "Philosophical Transactions of the Royal Society of
London" dated February 25, 1808, in which he gives an account of the
first industrial gas-lighting, he states:

It is now nearly sixteen years, since, in a course of
experiments I was making at Redruth in Co