8 
Stea7ii Engine^ 
fresh fuel, in its way to the flues or chimney, to pass, to- 
gether with a current of fresh air, through, over, or among, 
fuel which has already ceased to smoke, or which is con- 
verted into cokes, charcoal, or cinders, and which is in- 
tensely hot ; by which means the smoke and grosser parts 
of the flame, by coming into close contact with, or by be- 
ing brought near unto, the said intensely hot fuel, and by 
being mixed with the current of fresh or unburnt air, are 
consumed, or converted into heat, or into pure flame free 
from smoke. I put this in practice, first, by stopping up 
every avenue or passage to the chimney or flues, except 
such as are left in the interstices of the fuel, by placing the 
fresh fuel above, or nearer to, the external air than that 
which is already converted into cokes or charcoal ; and by 
constructing the fire-places in such manner that the flame, 
and the air which animates the fire, must pass downwards, 
or laterally, or horizontally, through the burning fuel, and 
pass from the lower part, or internal end or side, of the 
fire-place, to the flues or chimney. In some cases, after 
the flame has past through the burning fuel, I cause it to 
pass through a very hot funnel, flue, or oven, before it 
comes to the bottom of the boiler, or to the part of the fur- 
nace where it is proposed to melt metal, or perform other 
office, by which means the smoke is still more effectually 
consumed. In other cases, I cause the flame to pass im- 
mediately from the fire-place into the space under a boil- 
er, or into the bed of a melting or other furnace. The 
drawing Figure 1 (Plate I.) shews a section of a fire^ 
engine boiler, and its furnace or fire-place, which I have 
chosen for an example of the application of this new me- 
thod to the heating and evaporating of water. A A is 
the boiler, which may be made of any form suitable to 
its use. B B is a flue, surrounding the boiler as usual. 
C is the uptake, or passage from the space under the boil- 
er to the flues, D D is a funnel or flue for the flarn.e to 
