onsists, as will be seen in engraving
above, of a series of vertical U-shaped pipes, of wrought iron, 50
millimeters (2 inches) in diameter. The two legs of the U are of
unequal length; the longer being about 5 feet, and the shorter 3 feet
(exclusive of the bend at the top). Beneath the open end of the
shorter leg of each pipe is placed a burner, attached to a horizontal
gas-pipe, which turns upon an axis. The object of having this pipe
rotate is to bring the burners into an inclined position--shown by the
dotted lines in Fig. 2--for lighting them. On turning them back to the
vertical position, the heated products of combustion pass up the
shorter tube and down the longer, where they enter a common
receptacle, from which they pass into the chimney or out of doors.
Surrounding the pipes are plates of sheet iron, inclined at the angle
shown in Fig. 2. The object of the plates is to prevent the heated air
of the room from passing up to the ceiling, and send it out into the
room. To prevent any of the pipes acting as chimneys, and bringing the
products of combustion back into the room, as well as to avoid any
back-pressure, a damper is attached to the outlet receptacle. The
heated gas becomes cooled so much (to about 100 deg. Fahr.) that water is
condensed and precipitated, and collects in the vessel below the
outlet. Each burner has a separate cock, by which it may be kept
closed, half-open, or open. To obviate danger of explosion, there is a
strip of sheet iron in front of the burners, which prevents their
being lighted when in a vertical position; so that, in case any
unburned gas gets into the pipes, it cannot be ignited, for the
burners can only be lighted when inclined to the front. In starting
the stove the burners are lighted, in the inclined position; the chain
from the damper pulled up; the burners set vertical; and, as soon as
they are all drawing well into the tubes, the damper is closed. If
less heat is desired, the cocks are turned half off. It is not
permissible to entirely extinguish some of the burners, unless the
unused pipes are closed to prevent the products of combustion coming
back into the room. The consumption of gas per burner, full open, with
a pressure of 8/10, is said to be only 4-3/8 cubic feet per hour.

* * * * *

CONCRETE WATER PIPES.

Concrete water pipes of small diameter, according to a foreign
contemporary, are used in parts of France, notably for