their locomotives, and
steamers on the Volga are using the same fuel.

Wurtz experimented with crude petroleum in a reheating furnace at Jersey
City.

Dowson, Strong, Lowe, and others have devised systems for the production
of water gas.

These experiments, in general, have produced excellent results when
considered merely in the light of heat production, but, in advocating
their systems, the inventors seem to have overlooked the all-important
item of cost.

It is the object of this paper to show the impracticability of such
systems when considered from a commercial standpoint, so long as the
supply of coal lasts, and prices keep within reasonable limits.

In many cases, authors on the subject have given purely theoretical
results, without allowing for losses in the furnace.

The fuels to be considered are anthracite and bituminous coals, crude
petroleum, and coal, generator and water gases.

The average compositions of these fuels (considering only the heating
agents), as deduced from the analysis of eminent chemists, are:

PERCENTAGE BY WEIGHT.

________________________________________________________
| C | H | O | CO |CH_{4}|C_{2}H_{4}
+----+-----+---+----+------+----------
Anthracite |87.7| 3.3 |3.2| | |
Bituminous |80.8| 5.0 |8.2| | |
Petroleum |84.8|13.1 |1.5| | |
Coal gas | | 6.5 | |14.3| 52.4 | 14.8
Generator gas | | 1.98| |35.5| 1.46|
Water gas | | 6.3 |0.6|87.8| 1.2 |
------------------+----+-----+---+----+------+----------

We will employ the formula of Dulong--

h = 14,500 C + 62,000 (H - O/8)

to compute the theoretical heating powers of these fuels. In the case of
methane, CH_{4}, the formula is not true, but the error is not great
enough to seriously affect the result. This gives for the combustion of
one pound of:

Anthracite 14,500 Br. Heat Units.
Bituminous 14,200 " " "
Petroleum 20,300 " " "
Coal gas 20,200 " " "
Generator gas 3,100 " " "
Water gas 8,500 " " "

Reducing the above to terms of pounds of water evaporated from 212 deg. F.,
we have:

POUNDS OF WATER EVAPORATED FROM 212 deg. F.

Anthracite 15.023
Bituminous 14.69
Petroleum