ater" for "hot-air furnace," and we have the
assurance of the man across the way who sells boilers and radiators.

The beauty of it is that each proves his case to one's entire
satisfaction--not only that his own system is a marvel of perfection,
but that the other systems are dangerous to health and breeders of
unhappiness and really ought (though he wouldn't like to say so) to be
prohibited by law.

So we shall have to decide the question for ourselves. If we err, we
can still abuse the dealer, or the architect, or the contractor, for
letting us make a mistake.

THE HOT-AIR FURNACE

The hot-air furnace costs least to install. (We leave stoves out of
consideration.) It is also supposed to be easiest to manage. That, in
a sense, is true. A good furnace will act pretty well even under
indifferent direction; a bad one cannot be made much worse by the
greatest of stupidity.

However, the average person can run the average furnace with a fair
degree of satisfaction to the household, if not to himself. For a
house of six to eight rooms the furnace may be considered an efficient
means of heating. It requires more fuel than some other apparatus, but
there are compensations.

Since ventilation and heating are inevitably associated, the argument
that the furnace provides for ventilation is a strong one. If the air
is taken from outdoors, passed over the radiating surface into the
rooms, and then sent on its way, something like perfect ventilation is
assured. If the air is simply taken from the basement--a poor place to
go for air--heated, passed through the rooms, returned, and heated over
again, we may well pray to be delivered from such "ventilation." The
success of the furnace depends not upon ability to keep up a rousing
fire but upon a proper regulation of air currents. Many a first-class
furnace, properly installed, fails to work satisfactorily because the
principle of heating is not understood. Even with the best of
knowledge, the air is hard to regulate, and the very principle that
gives the furnace its standing as a ventilator must prevent it from
being a perfect heater.

Unless some artificial moisture is provided, not only will the air be
too dry for comfort and health, but an excessive degree of heat must be
attained in order to warm the rooms, thus increasing the consumption of
coal. A water pan is usually provided in the furnace, but too often it
is neglected.

DIRECTION OF HEAT

I