femNEDY D ] USE 0F THE 0IL AS FUEL. 159 
ton with oxygen calorimeter is 10000 B. T. II., giving a mean of 11)224 
B. T. U. The calorific value of Pennsylvania and Ohio crude petro- 
leum is about 20200 B. T. IT., and that of Baku, Russia, crude about 
19500. It will thus be seen that the calorific value of the Beaumont 
petroleum compares favorably with that of the best liquid fuels in 
use. 
SAFETY. 
Liquid fuel, however, requires other qualifical ions than merely high- 
heating values. It must be safe for transportation, handling, and for 
storage. Very few petroleums as they come from the well have these 
qualifications. All contain a greater or less percentage of naphtha or 
some of the lighter hydrocarbons which have a tendency to reduce 
the flash point and make the oil easily inflammable. Consequently a 
liquid fuel to be safe should not contain any of these light inflamma- 
ble oils, nor should it contain naphtha. According to Oliphant, fuel 
oils should have a gravity of between 20° and 25° B (sp. gr. 0.9333 to 
1.9032) and a flash test of from 240° to 270° F. The Asfatka, or fuel 
oils of the Russian fields, have a specific gravity of 21° B (0.928) and a 
flash point of about 284° F., while those of the Eastern Archipelago 
have a specific gravity of 0.970 and a high flash point. 
The effect of a mixture of the lighter oils with the petroleums is the 
tendency to create an inflammable vapor in connection with their stor- 
age, which, mixed with air, becomes highly explosive. It has been 
found that a mixture of only 2 per cent of air with this vapor makes 
an explosive mixture, and that upon dilution to 4 percent or over the 
mixture is harmless, although still inflammable. 
The few tests of the Beaumont oils have shown them to contain a 
small quantity of light oil, and to have a flash point correspondingly 
low. The flash point as determined ranges between 110° to 180° F. for 
Beaumont and 244° F. for the oils from the Sour Lake shallow wells. 
These oils, however, appear to be very slow in the generation of 
inflammable gases. Two tanks in the Beaumont fields have already 
been struck by lightning without any explosion or even serious fire 
taking place, and Professor Denton, in a series of experiments, shows 
that the Beaumont oil does not give rise to an inflammable vapor 
until heated to above 142° F. For complete safety, however, these 
oils should be distilled so as to remove enough of the lighter constit- 
uents to bring the flash point up to about 240°, although they have 
been and are now being utilized with apparently perfect safety for fuel 
purposes in their crude condition. 
The introduction of earthen and practically open tanks, allowing 
the lighter products to escape by a process of natural distillation, may 
be expected to bring them within the safety limits as to flash point 
without further treatment. 
