Weight of barrel of 50 gallons Tar 516 lbs.

If, however, we assume an evaporation of 14 lbs. per lb. tar, its value becomes per barrel of 50 gallons,

$1.38.

WATER GAS TAR.

I was unable to find any data regarding the use of water-gas tar as fuel, or any ultimate analysis from which it could be computed. It was therefore necessary to have an analysis made, and I give below the results of careful analysis and calorimeter tests.

The tar used comes from gas oil used in a standard Lowe set. The tar from the set is run to a tar tank having a capacity of some 500 barrels. The hot water from the seal and washer is sufficient to maintain the contents of the tank at about 135°. When the accumulation in the tank has reached a hundred barrels or so it is pumped from the bottom and burned without further separation.

In the sample taken from the regular boiler supply, about 2% of water separated by further heating in a vessel immersed in hot

water.

ANALYSIS OF WATER-GAS TAR FROM GAS OIL.

CALORIMETER TEST OF WATER-GAS TAR FROM GAS OIL.

The heating value as determined by a bomb calorimeter was

17,193 B.T.U.

equivalent to an evaporation from and at 2120 of

17.8 lbs. water.

The heating value as determined by calculation from the analysis in the manner before referred to was

17,296 B.T.U.

equivalent to an evaporation from and at 2120 of

burner before referred to.

17.9 lbs. water.

Large quantities of the tar have been burned as it accumulated, and the results have been better, as we became more familiar with its use. It has been burned in the furnace and with the It is more easily handled than the coal tar, being more liquid, and has less tendency to form carbon. It burns with a clear white flame, with no smoke or deposited carbon.

The following table shows the result of the latest test.

would have a fuel value by calculation of 20,789 B.T.U. Poole states American oil as having values from 18,000 to 21,000 B.T.U. equivalent to an evaporation of from 18.5 to 21.5 lbs. water. Barrus in his Boiler Tests gives the results of three experiments as 11.96, 13.66, and 15 lbs. from and at 212°. From this comparison of theoretical and practical values, it would seem as if the watergas tar was being well utilized.

Its value compared with our assumed standard would be found as follows:

Weight of barrel of 50 gallons water-gas tar, 479 lbs.

$5.70 per ton.

It would appear from the theoretical and practical results cited above, that if steam coal is selling for $3.75 per ton of 2,000 lbs., a fair market value for fuel residuals would be:

If the price of steam coal varies, the value of the residual would also vary; but with the broad market at our door, there is little reason for going below this price.