NITRATES FROM ATMOSPHERE — SCOTT. 379 



generating units of 25,000 kilowatts, which are now being made, 

 there is no reason why the cost per kilowatt should not come down 

 as low as for Norwegian hydroelectric plants. Further, if instead 

 of burning the coal in boilers it is made into gas and by-products 

 are recovered, it seems likely that we shall be able to generate 

 electricity as cheaply as the average for Norway. 



To show what can be done by a producer-gas power plant, the 

 following estimate by Mr. Chorlton, of Messrs. Mather & Piatt, is 

 of interest: 



Producer-gas engine power station for 3,000 brake horsepower. 



Capital costs: 



Four 1,000 brake horsepower gas engines complete ; coupled to four 

 electric generators starting air compressor; gas, air, water, and 



exhaust pii>es; and water pumps £21,850 



Buildings, engine foundations, crane, and silencer 2,770 



Exhaust heat boilers 1,600 



Switchboard and wiring 1,500 



Water tank and cooling tower 400 



Capital cost 28,120 



This is equal to £7.03 per brake horsepower, or £10.545 per kilowatt. 

 Running costs, on the basis of 300 twenty-four-hour working days per 

 annum : 



Oil, waste, and stores 650 



Repairs, rates and taxes, maintenance, insurance, etc., at O.Old. 



per brake horsepower hour 900 



Wages — Three shifts of one man at 40s. 1 

 Three shifts of one man at 35s. j 

 Interest and depreciation at 10 per cent 2,812 



Total running cost per annum 4,947 



Assuming the interest and depreciation to be only 6i per cent, the total 



running cost is 3,892 



The capital cost of a Mond producer plant capable of giving gas for 



3,000 brake horsepower is 13.200 



The running cost of a Mond producer-gas plant is : 



9,600 tons of shale Nil. 



900 tons of belt pickings Nil. 



1,500 tons of waste slack, at 4s. per ton 300 



600 tons of washed slack, at 8s. per ton 240 



Maintenance, including rates, taxes, labor (including packing), steam 



power, repairs, stores, etc., at 2s. 6d. per ton 1,500 



Sulphuric acid, at 35s. per ton 665 



Interest and depreciation, at 30 per cent 1,320 



Running cost per annum 4,025 



