

CHAPTER XXX 

 ARTIFICIAL LIGHTING 



WE seldom consider what life would be without our wonder- 

 ful methods of illumination which turn night into day, and 

 prolong the hours of work and pleasure. Yet it was not until 

 the nineteenth century that the marvelous change was made 

 from the short-lived candle to the more enduring oil lamp. 

 Before the coming of the lamp, even in large cities like Paris, 

 the only artificial light to guide the belated traveler at night 

 was the candle kept burning in an occasional window. 



With the invention of the kerosene lamp came more efficient 

 lighting of home and street, and with the advent of gas and 

 electricity came a light so effective that the hours of business, 

 manufacture, and pleasure could be extended far beyond the 

 setting of the sun. 



The candle. In the early days of civilization, man secured 

 modest illumination by burning wicks soaked in fats. Liquid 

 fat was poured into a metal vessel and a wick was inserted 

 in an opening in the cover. Later, this crude device was re- 

 placed by the more convenient candle. Originally, candles 

 were made by dipping a wick into melted tallow, withdrawing 

 it, allowing the adhered tallow to harden, and repeating the 

 dipping until a satisfactory thickness was obtained. The more 

 modern method consists in pouring a fatty preparation into a 

 mold, at the center of which a wick has been placed. 



A wick, when lighted, burns for a brief interval with a faint, 

 uncertain light; almost immediately, however, the intensity 

 of the light increases and the illumination remains good as 



CLARK INTRO. TO SC. l8 2 J$ 



