Artificial Lighting 



159 



the work of Dr. John Clayton (1739) and Thomas Shirley 



(1759). Murdock introduced the use of gas for lighting into 



several factories; and by 



1805 Manchester was light- j-jj 



ing its cotton mills with coal .90 



gas. Progress in its use .'TO 



was fairly rapid. London ; 



shortly after 1810 made it ;JJ 



the chief illuminant ; Paris 



began its use in 1820 ; Bal- 



ELECTRIC L 



1896 1898 1900 1902 1904 1906 1908 1910 1912 1914 1916 



timore in 1821; Boston FlG> 44 A. Graphic illustration of 

 in 1822 ; and New York tne decrease of cost of electric lighting 

 f^.. T. , ,. ! , , in twenty years. 



City, which did not intro- 

 duce it before 1823, had it in common use by 1827. 



60. Modern lighting. The chief means of illumination 

 to-day are kerosene oil, electricity, and artificial gas, which may 



FIG. 44 B. The cost of electric current for lighting has decreased greatly 

 since the year 1880. The relative candle power purchased by the same money 

 in given years is shown graphically. 



