[Illustration: IMPROVED GAS BURNER. FIG. 2.--Section through A B.]

The light is simply that produced by an arrangement of a kind of Argand
burner turned upside down. The central gas-pipe, _a_ (Figs. 1 and 3), is
connected to a distributing chamber, whence the annular cluster of brass
tubes, _a', a_, (Figs. 1 and 2), are prolonged downward, forming the
burner. The burner is inclosed in an iron or brass annular casing, b, b,
which forms the main framework of the apparatus. The annular space which
it affords is the outlet chimney or flue for the products of combustion
of the burner beneath, and is crossed by a number of thin brass tubes,
c, c, which lead from the outer air into the inner space containing
the burner tubes, a', a', already described. The upper openings of the
annular body, b, are shown at e, e (Fig. 3), which communicate direct
with the chimney proper, e', e'. The burner is lighted by opening the
hinged glass cover, d, which fits practically air-tight on the bottom
of the body, so that the air needed to support combustion must all pass
through the tubes, c, c, the outer ends of which are protected by the
casing, k, k.

[Illustration: IMPROVED GAS BURNER. FIG. 3.--Section through C D.]

When the gas is lighted at the burner, and the glass closed, the burner
begins to act at once, although some minutes are necessarily required
to elapse before its full brilliancy is gained. The cold air passes in
through the tubes provided for it, and when these are heated to the
fullest extent on their outside, by the hot fumes from the burner, they
so readily part with their heat to the air that a temperature of 1,000 deg.
to 1,200 deg. Fahr. is easily obtained in the air when it arrives inside,
and commences in turn to heat the burner-tubes. The air-tubes are placed