158 OIL FIELDS OF TEXAS-LOUISIANA COASTAL PLAIN, [bull. 212. 
FUEL. 
THEORETICAL VALUE. 
The value of any fuel depends upon several considerations. Com- 
mercially, upon its location and capability of successfully competing 
with the other fuels that may be brought into the same market. These 
conditions are largely governed by the cost of production, length of 
haul, and cost of transportation and handling. Under certain con- 
ditions it may be possible for an inferior fuel to successfully compete 
with and even supplant a much higher grade fuel. Thus wood has 
been enabled in many localities to compete successfully with coal. 
Under similar conditions coal has been enabled to meet the inroads 
of gaseous or liquid fuel in its various forms. 
Technically, fuels are graded by the work they will perform. This 
is determined either theoretically from the chemical composition or 
by practical tests, and the results obtained by these two methods 
often vary widely. It is a well-known fact that many, if not all, coals 
have a calculated theoretical calorific value much greater than they 
really possess, as shown in their ordinary use or even as measured 
by a calorimeter. 
In the testing of fuels the heat value as determined by their chem- 
ical composition is the best method yet devised, at least for compar- 
ison of new and untried fuels. By this means their relative value as 
compared with other well-known fuels may be determined and some 
idea be gained as to their approximate commercial values. By cal- 
culating the theoretical heating power various uncertain quantities 
are eliminated, such as style of and condition of grates, method of 
setting and form of boiler, draft, and a number of other conditions 
which can not be rendered uniform. In the testing of liquid fuel 
there are the questions of the size and style of burner, quantity of 
steam or air, or both, admitted to (ire box, and a number of other 
practical conditions, all of which have a direct effect on the result 
and greatly complicate the problem. 
The theoretical value of any fuel depends upon its constituents and 
upon their mode of arrangement. Carbon and hydrogen are consid- 
ered the essential heat jnoducers. The other constituents being gen- 
erally present in small quantities are usually disregarded, with the 
exception of sulphur and ash. Sulphur is generally considered as a 
deleterious constituent of any fuel, not only on account of its low 
heat power, but also on account of the readiness with which it com- 
bines with the metals in the furnace. Where fuel is intended for 
metallurgical purposes it is required to be as free from sulphur and 
sulphurous compounds as possible. 
The ultimate calorific value of Beaumont petroleum as determined 
by Redwood is 19388 B. T. IL, and as determined by Professor Den- 
