18 Petroleum as Fuel. 
G, above the coil, to the retort or mixer, 4, where combining 
with the vapour of oil from the coil, it passes into the 
straight pipes, /V, under the coil, /. The flame was vivid 
and intense, regulated in its force by the relative flow of oil 
and steam, and was entirely under the control of the fireman 
who, at his pleasure, could reduce the flame to the flicker 
of an expiring lamp, or extend it by a single movement to 
a volume filling the large flues and furnace with its flame 
No smoke or unpleasant smell was perceptible, and the 
combustion was complete and entirely manageable. Steam, 
at atmospherie pressure, was raised in the boiler in twenty- 
nine minutes from the time of admission of oil into the 
coil. No measure was taken in this experiment of the 
amount of water evaporated ; the apparatus not being con- 
sidered as properly proportioned to exhibit the economical 
value of the fuel, and the experiment terminated in one 
hour by closing the oil cock, 1/—and the fire was out. 
The analysis of this experiment may be shown as follows. 
As this experiment only exhibited the weight of oil 
which consumed under the boiler, raised a given quantity 
of water from a temperature of 60° to the boiling point, it 
is requisite for a comparison with the known effects of an- 
thracite coal, to show the proportionate amount of oil 
which would be necessary to convert this same bulk of 
water into steam of the atmospheric pressure, or the weight 
of water which a pound of this fuel will convert into steam. 
According to Tredgold, the quantity of fuel which will 
convert a cubic foot of water, of a given temperature, into 
steam, at the pressure of the atmosphere, is obtained by 
multiplying the quantity of fuel which will heat a cubic 
foot of water one degree, by the sum of the latent heat of 
steam, and the difference between 210 deg. and the given 
temperature of the water. In this case, 212 deg.—6o deg. 
=152deg. The latent heat of steam, according to Dr. 
Ure, is 967 deg., which added to 152 deg. — 1,11@ pea, 
which multiplied by the quantity of fuel which will heat a 
cubic foot of watcr one degree, will give the weight of fuel 
requisite to convert a cubic foot of water from the tempera- 
ture of 60 deg. into steam. This product multiplied by the 
number of cubic feet of water to be converted into steam, 
will give the total amount of fuel required in this case. 
Making the proper allowance for the pine wood in light- 
ing fires, the weight of oil consumed in the experiment was 
sixty pounds; the contents of the boiler was 200 cubit feet 
at a temperature of 60 deg., which was heated by this 
