280 



ARTIFICIAL LIGHTING 



The cost of an acetylene generator is about $50 for a small 

 house, and the cost of maintenance is not more than that of 

 lamps. The generator does not require filling oftener than once 

 a week, and the labor is less than that required for oil lamps. 

 In a house in which there were twenty burners, the tanks were 

 filled with water and carbide but once a fortnight. Acetylene 

 is seldom used in large cities, but it is very widely used in 

 small communities and is particularly convenient in more or 

 less remote summer residences. 



Electric lights. The most recent and the most convenient 

 lighting is that obtained by electricity. A fine, hairlike fila- 

 ment within a glass bulb is raised to incandescence by the heat 

 of an electric current. 



