Improvement in Steam Engine Boilers. 11 
and are inflammable on coming in contact with flame or fuel ata red 
heat, such as anthracite coal walle ignited. 
I make the said receiver, or generator of the vapor, of a suitable 
form and size to receive the combustible fluids; and with surface 
enough for the air to pass over to take up and receive its charge, 
when it is led by a pipe to the furnace ; and when circumstances 
permit hot and dry air to be admitted, it will take up the vapor more 
freely. 
The introductory pipe or pipes, must each have a cock, not far 
from the furnace, to govern the supply ; and between the cock and 
the furnace, a wire-gauze screen, on the principle of the safety lamp 
of Sir Humphry Davy: and to keep the same free from obstruction, 
I sometimes cause a small stream of steam, led from the boiler, to . 
enter behind the screen of wire gauze, and strike it in the direction of 
the course of the current of vapor continually or occasionally, and with 
the more sure advantage when the temperature is high, and the pipe 
prolonged in the furnace very hot ; when some additional portions of 
hydrogen may be obtained from its decomposition. 
he boiler of the engine, when this auxiliary fuel is to be used, 
should be made with proper adaptation to this intention.. Whatever 
the size or form of the boiler, the bottom of the furnace will be oc- 
cupied with a narrow grate of coal. When the boiler is made of 
four long cylinders, in the manner of my anthracite coal furnace- 
boiler, then this improvement thereon can be conveniently applied ; 
the introducing tubes being so arranged as to direct the vapor upon 
or into the most lively part of the fire. When the boiler is for loco- 
motive engines, the furnace will be more conveniently placed in an up- 
right cylindrical boiler, with a reverberatory roof or dome within, that 
will be covered with water ; the flue leading into a long horizontal 
part, or into other upright divisions of the cylindrical boiler, tll the 
heat is principally imparted to the water. 
But as the flame thus produced, demands a large supply of oxy- 
‘gen from the atmosphere, and if it were received wholly through the 
grate, it might not only cause the coal to consume disproportionably 
fast, but the air be deficient in oxygen, I supply it by means of 
air tubes around the furnace, with convenient stopples or stop cocks, 
io regulate the quantity, and wholly stop it when anthracite coal alone 
is used ; the air tubes in passing in, contracting to a small orifice to 
increase the velocity of the air—an exhauster of the funnel or chim- 
ney, a fan wheel, as usual, operating to increase the draft. 
