ELECTRICITY AT THE WORLD'S FAIR. 49 



of a hundred per cent. The consi ? .mer, therefore, can have in an 

 available form not more than ten per cent and probably not over 

 seven per cent of the heat in the fuel with which the cycle of 

 operations started. This is an efficiency much below that obtain- 

 able from the direct combustion of the fuel by even the most 

 wasteful methods, and at no price at which electrical energy can 

 be furnished could the two forms of heating be brought on the 

 plane of economic equality. A direct comparison of the actual 

 number of heat units (pound-degree Fahr.) present in each in- 

 stance will show with perhaps greater clearness the economic re- 

 lations of the two methods of heating. A horse power of elec- 

 trical energy is equivalent to 2,565 heat units per hour. A pound 

 of coal contains 13,000 heat units, and costs, with coal at five dol- 

 lars per ton of 2,000 pounds, a quarter of a cent. If we give to 

 the coal an efficiency of but ten per cent, it will require two 

 pounds to equal the available heating power of the electrical 

 horse power, allowing that all the heat in the latter case is- 

 utilized. This will cost the user half a cent, and making due 

 allowance for the collateral expenses of coal as a fuel, such as 

 kindling, removal of ashes, and cost of handling, it is very evi- 

 dent that electricity can not hope to offer any economical com- 

 petition. The commercial promoters of electrical heating count 

 upon a charge to the consumer of five cents per horse power per 

 hour for cooking purposes, and a cent and a half for heating pur- 

 poses. This is very much under the figures at wnich electric 

 power is now being furnished for lighting purposes the charge 

 for this being at the rate of from twelve to fifteen cents per horse 

 power-hour but it is proposed to make the same discrimination 

 between light and heat that the gas companies have instituted. 

 At the lower figure electric heating is nearly three times, and at 

 the higher nearly ten times, as expensive as that by coal, allot- 

 ting to coal the above very low duty. But coal has no such low 

 efficiency. The radiant heat from hard coal is fully twenty-five 

 per cent of the total heat generated, and of this fully one half is 

 utilized in a grate fire, which is the most wasteful of the heating 

 devices in use. In the best forms of grates which have been de- 

 vised, in which the surplus heat is used to warm the air supply 

 of the room, as much as thirty-five per cent of the heat may be 

 made available, while in close stoves of the best patterns the effi- 

 ciency will not fall below seventy per cent. 



With gas the comparison is of course much more favorable, as 

 here the cost of a unit of heat is much greater than in the case of 

 coal. Illuminating gas has a heating value of six hundred and 

 fifty to eight hundred heat units per foot, according to the qual- 

 ity of the gas. At the lower figures it requires a trifle under 

 four feet to equal the heat value of an electrical horse power. 



