me by the current of air produced, and partly to
its distance from the objects to be illuminated.

The great difficulty which in the whole history of ventilation has
opposed itself to the adoption of proper arrangements for removing the
products of combustion has been the necessity of bringing the tube to
carry off the gases low down into the room, and of incasing the burner
in such a way that none of the products should escape; but with the
present revolution in gas burners this necessity is entirely done away
with, and the regenerative burner offers the means not only of
removing all the products of combustion but also of effecting thorough
ventilation of the room itself, as experiments made some few years ago
showed me that a ventilating regenerative burner, burning 20 cubic
feet of gas per hour and properly fitted, will not only remove all its
own products of combustion, but also over 5,000 cubic feet per hour of
the vitiated air from the upper part of the room. I am quite aware
that many regenerative lamp makers raise various objections to fitting
ventilating lamps, these being chiefly due to the fact that it
requires considerable trouble to fit them properly; but I think I have
said enough to show the absolute necessity of some such system, and
when there is a general demand for ventilating lamps, engineering
skill will soon find means to overcome any slight difficulties which
exist.

Having disposed in a few words of a subject which, if fully treated,
would occupy a long course of lectures by itself, I will pass on to
the consideration of gas as at present used as a fuel.

There is no doubt that gas is the most convenient and in many ways one
of the best forms of fuel for heating and cooking purposes, and the
efforts which all large gas companies are now making to popularize and
increase the use of gas for such purposes will undoubtedly bear fruit
in the future. But before the day can come for gas to be used in this
way on a large scale, there is one fact which the gas manager and gas
stove manufacturer must clearly realize and submit to, and that is
that no gas stove or gas water heater, of any construction, should be
sent out or fitted without just as great care being taken to provide
for the carrying away of the products of combustion as if an ordinary
fuel range was being fitted. Do not for one moment allow yourself to
be persuaded that, because a gas stove or geyser does not send out a
mass of black smoke