COAL "During this period (9 months) the highest monthly cost per ton of dry charge treated was $8.49, and the lowest cost was $4.75. The highest cost per ton for coal alone was $6.i6, and the lowest was $3.32. The highest percentage of coal used was 61 and the lowest was 33.6 per cent. It should be noted that the least coal consumption occurred during the two months in which we used the pulverized coal, and during which there was no steam generated from the waste gases. The average net cost, giving fuel credit to the rever beratory for the period in question, was $5.49 per ton made up of the following costs: Labor, $o.795; sup plies, $o.293; coal, $4.o67; power, $o.177; miscella neous, $o.13 ; repairs, $o.358; flux, $o.oi ; total, $5.83; from which is deducted a steam credit of $0.34; leaving a net cost of $5.49 per ton smelted.
"The works closed down in the latter part of Octo ber, 1907, and experiments were stopped for the time being, but it was thought we had proceeded far enough to demonstrate that the coal obtainable from the Southwest was not well adapted to reverberatory practice." OIL "Costs for Five Months in 1908.
Labor, operating and repairs.. . . $14,829.39 Shop expense 1,966.64 Supplies (firebrick, etc.) . . . . 5,613.13 Oil Fuel 56,217.15 Power 445.83 Miscellaneous expense Total $79,605.92 Cost of barren fluxes 609.90 Total $80,215.82 Less steam credit 24,267.37 Net account smelting Average cost per dry ton smelted, $1.785 "The actual water evaporated per pound of oil burned in the reverberatory was 6.74 lbs., whereas the pound of oil burned under the smeltery power-house boiler evaporated 13.96 lbs. Taking account of the temperature of feed water and converting into evapo ration from and at 212 degrees F., we have the follow ing figures: Evaporation per pound of oil burned in reverberatory, 7.45 lbs. Evaporation per pound of oil burned under power-house boilers 16.08 lbs.
"Costs Per Ton Smelted, First Six Months of 1909: Labor, operation. $0.24 Labor, repairs. o.16 Supplies. 0.22 Oil Fuel. Power. 0.02 Miscellaneous. o.o8 Total direct costs. $2.45 Cost of fluxes. o.o8 $2.53 Steam credit. 0.77 Net cost. $1.76"