13 
Steam E?igine. 
provement, a very considerable saving of fuel is effected 
from the immediate conversion of the whole, or very near- 
ly the whole of the smoke arising from the fuel into flame : 
first, the said invention in principle consists in supplying 
the burning fuel more fully with air, having this fuel more 
in a body together, and a less quantity in combustion, at the 
same time, than what usually takes place in other furnaces, 
which are applied to the same uses; in applying the fuel 
with a portion of fresh air, admitted from an opening made 
for that purpose, and directed in such a manner as it may 
come in contact with the smoke from the kindling coal 
and great heat of the furnace together, and the fuel being 
more fully supplied with air, and consequently a greater 
degree of heat taking place, and the smoke and fresh air 
uniting in the great heat, the smoke is inflamed, and ren- 
dered useful in adding to the heat of the furnace ; besides, 
this portion of fresh air is so conducted as to act partly on 
the kindling or kindled fuel, and raising it to a greater 
degree of heat, after it has served its purpose by uniting 
with and inflaming the smoke ; and therefore is employed, . 
in some measure, usefully, even after the coal has ceased 
to smoke : secondly, to the above may be added, the form 
of the furnace, which is so constructed, that the full kind- 
led fuel is kept backward in the furnace, while the fresh coal 
lies before, and is more gradually kindled than if intro- 
duced further among the full kindled fuel, while the heat 
of the furnace is little injured or damped by the introduc- 
tion of fresh coal, as is more fully described in the practi- 
cal description of the furnace. The coal is admitted into 
the furnace by a hopper, feeder, or mouth-piece, A (Fig. 
7 and 8), made of cast iron (but which may be made of 
other materials), and inclined to the horizon, as in Fig. 7 ; 
so that the coal in it, may in some measure, fall into the 
fire-place, above the bars, as the fuel is spent ; in the up- 
per part of this hopper, feeder, or mouth-piece, is a Plate, 
