21.00
Coal gas 20.87
Generator gas 3.21
Water gas 8.7

The results of experiments show the efficiency of fluid-burning furnaces
to be about ninety per cent., while with coal sixty per cent. may be
taken as a good figure. The great difference in the efficiencies is due
to the fact that fluid fuels require for combustion very little air
above the theoretical quantity, while with the solid fuels fully twice
the theoretical quantity must be admitted to dilute the products of
combustion.

Correcting our previous results for these efficiencies, we have:

POUNDS OF WATER ACTUALLY EVAPORATED FROM 212 deg. F., PER POUND OF FUEL.

Anthracite 9.0
Bituminous 8.8
Petroleum 18.9
Coal gas 18.8
Generator gas 2.9
Water gas 7.8

These figures agree closely with the results of experiments.

We will now consider the subject of cost.

The following cities have been selected, as manufacturing centers,
termini of railroads, or fueling ports for steamers.

In the case of petroleum, as it is rarely shipped in the crude state, an
approximation is made by adding to the cost at the nearest shipping port
the freight charged on refined petroleum, and ten per cent. to cover
duties and other charges.

Owing to the difficulty of obtaining prices, in some of the cities,
there may be some errors.

COSTS. MARCH, 1884.

Anthracite Bituminous Coal gas
per ton of per ton of per 1,000
2,240 lb. 2,240 lb. cubic feet.

New York $4 00 $4 25 $1 75
Chicago 5 00 3 50 1 25
New Orleans 6 00 3 50 3 00
San Francisco 12 00 7 50 3 00
London 5 00 3 00 0 75
Port Natal 12 50 11 00
Sydney 12 00 7 00
Valpariso 11 50 7 50

Generator Crude Water gas
gas per 1,000 Petroleum per per 1,000
cubic