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DEFTY'S IMPROVEMENTS IN GAS BURNERS AND HEATERS.


Among other inventors who have turned their attention to gas consumption
is to be found Mr. H. Defty, who has made several forms both of heating
and lighting burners. Mr. Defty has sought in the latter to apply the
principle of heating the air and gas in a simple manner, with the object
of obtaining improved photometrical results. The double-chimney
Argand, as tried many years since by Dr. Frankland and others, makes
a reappearance in one of Mr. Defty's models, illustrated in the
accompanying diagram (Fig. 1).

[Illustration: Fig. 1.]

Here we have the double-chimney, a and b, for heating the air supplied
to an ordinary Argand, by causing it to pass downward between the two
chimneys, and inward to the point of combustion through a wire-gauze
screen, c, under the inner chimney; but, in addition thereto, Mr. Defty
hopes to gain an improved result by causing the gas to pass through the
internal tube, s, which rises up in the middle of the flame. The gas,
which enters at e, is made to pass up through the inner tube and down
through the annular space to the burner.

[Illustration: Fig. 2.]