and to discourage the
invention of economical burners, in order that the consumption might
reach a maximum. The application of gas for heating purposes had not been
encouraged, and was still made difficult in consequence of the
objectionable practice of reducing the pressure in the mains during
daytime to the lowest possible point consistent with prevention of
atmospheric indraught."

The introduction of an important rival into the field in the shape of the
electric light has now given a powerful impetus to the invention and
introduction of effective gas-lamps, and amongst inventors of recent
years no name is, perhaps, in this respect so well known as the name of
Sugg. As long as gas retained almost the monopoly, there was no incentive
to the gas companies to produce an effective light cheaply; but now that
the question of the relative cheapness of gas and electricity is being
actively discussed, the gas companies, true to the instinct of
self-preservation, seem determined to show what can be done when gas is
consumed in a scientific manner.

In order to understand how best a burner should be constructed in order
that the gas that is burnt should give the greatest possible amount of
illumination, let us consider for a moment the composition of the gas
flame. It consists of three parts, (1) an interior dark space, in which
the elements of the gas are in an unconsumed state; (2) an inner ring
around the former, whence the greatest amount of light is obtained, and
in which are numerous particles of carbon at a white heat, each awaiting
a supply of oxygen in order to bring about combustion; and (3) an outer
ring of blue flame in which complete combustion has taken place, and from
which the largest amount of heat is evolved.

The second of these portions of the flame corresponds with the "reducing"
flame of the blow-pipe, since this part, if turned upon an oxide, will
reduce it, i.e., abstract its oxygen from it. This part also corresponds
with the jet of the Bunsen burner, when the holes are closed by which
otherwise air would mingle with the gas, or with the flame from a
gas-stove when the gas ignites beneath the proper igniting-jets, and
which gives consequently a white or yellow flame.

The third portion, on the other hand, corresponds with the "oxidising"
flame of the blow-pipe, since it gives up oxygen to bodies that are
thirsting for it. This also corresponds with the ordinary blue flame of
the Bunsen burner, and