d of petroleum usually has a calorific value of
from 18,000 to 22,000 B. t. u. If an ultimate analysis of an average
sample be, carbon 84 per cent, hydrogen 14 per cent, oxygen 2 per cent,
and assuming that the oxygen is combined with its equivalent of hydrogen
as water, the analysis would become, carbon 84 per cent, hydrogen 13.75
per cent, water 2.25 per cent, and the heat value per pound including
its contained water would be,

Carbon .8400 x 14,600 = 12,264 B. t. u.
Hydrogen .1375 x 62,100 = 8,625 B. t. u.
------[**Should be .1375 x 62,000 = 8,525]
Total 20,889 B. t. u.[**Would be Total = 20,789]

The nitrogen in petroleum varies from 0.008 to 1.0 per cent, while the
sulphur varies from 0.07 to 3.0 per cent.

Table 46, compiled from various sources, gives the composition,
calorific value and other data relative to oil from different
localities.

The flash point of crude oil is the temperature at which it gives off
inflammable gases. While information on the actual flash points of the
various oils is meager, it is, nevertheless, a question of importance in
determining their availability as fuels. In general it may be stated
that the light oils have a low, and the heavy oils a much higher flash
point. A division is sometimes made at oils having a specific gravity of
0.85, with a statement that where the specific gravity is below this
point the flash point is below 60 degrees Fahrenheit, and where it is
above, the flash point is above 60 degrees Fahrenheit. There are,
however, many exceptions to this rule. As the flash point is lower the
danger of ignition or explosion becomes greater, and the utmost care
should be taken in handling the oils with a low flash point to avoid
this danger. On the other hand, because the flash point is high is no
justification for carelessness in handling those fuels. With proper
precautions taken, in general, the use of oil as fuel is practically as
safe as the use of coal.

Gravity of Oils--Oils are frequently classified according to their
gravity as indicated by the Beaume hydrometer scale. Such a
classification is by no means an accurate measure of their relative
calorific values.

Petroleum as Compared with Coal--The advantages of the use of oil fuel
over coal may be summarized as follows:

1st. The cost of handling is much lower, the oil being fed by simple
mechanical means, resulting in,

2nd. A general labor