HOUSE HEATING 



4i9 



Briquets. Briquets are now offered tor sale at about the 

 price of coal. They are made of coal screenings with a 

 little oil or asphalt for a binder. They make a good 

 fireplace fuel. 



Oils. Low-grade oils 

 for heating are not popu- 

 lar at a distance from oil 

 wells because of the freight 

 charges. Where oil is 

 plentiful, the railroads use 

 it exclusively. It is burned 

 most successfully where 

 pressure is convenient to 

 spray oil into the fire box. 



Gas. Gas, like coke, is 

 excellent for a high local 

 heat. Complete combus- 

 tion takes place within fig. 320 

 a small zone. For this 



After University of Minnesota 



Sectional boiler, showing water 

 columns and passages 



reason these fuels are not popular 

 in ordinary heaters where a large 

 combustion space is provided. 



Electricity. Electricity is expen- 

 sive for heating and cooking 

 purposes. An electric iron is the 

 only appliance which is economical 

 as compared to the old way. For 

 general purposes, electricity would 

 have to sell for 2}4 cents per kilowatt 

 hour to compete with coal for heating 

 and with gas and wood for cooking. 

 Prices now range from 10 to 15 cents 

 per kilowatt hour. 



Considerations and precautions. 



All-round steam and hot-water 



M^a&ZZa^a™* boilers are made for hard coal. A 



After University of Minnesota 



Fig. 321. Round, back- 

 connected hot-water boiler. 



