CHAPTER XIX 

 HOUSE HEATING 



HISTORICAL DEVELOPMENT 



Progress. Years of progress have developed at least six 

 styles of house-heating installation, aside from the old 

 familiar first method, the fireplace, in which from 80 to 90 

 per cent of the heat generated went up the chimney. Real 

 progress was made when the grate fire was moved to the 

 center of the room and incased in thin cast iron or sheet iron, 

 giving us the stove, and increasing the radiating surface 200 

 per cent. At the same time the size of the flue was reduced 



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After University of Minnesota 



Fig. 307. Jacketed stove or hot-air furnace with air ducts 



75 per cent and the large loss of heat characteristic of the 

 open grate fire was eliminated. Another step was made when 

 the stove was moved to the cellar and a jacket placed around 



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