12 GENERAL INTRODUCTION 



1883 " Three-wire " system first used. 



1884 Dr. J. Hopkinson clearly established the fact that similar alternators 

 . could be run as generators and motors. First practically demon- 

 strated in 1889 by Mordey. 



1884 American Institute of Electrical Engineers was organized. 



1885 First transformer built in this country by Wm. Stanley at Great 



Harrington, Mass. 



1885-88 Nicola Tesla and Galileo Ferraris invented independently the poly- 

 phase induction motor and pointed out the advantages of the three- 

 phaae system. 



1885 National Electric Light Association was organized in Chicago. 



1886 First regular 133-cycle, single-phase lighting plant was installed in 



Buffalo. 



1886 Criel-Paris transmission was completed. Twenty amperes direct- 

 current was transmitted for a distance of 25 miles at a potential of 

 7500 volts. 



1886 Sprague installed the first electric street railway in this country at 

 Richmond, Va. 



1886 The first A.C. transmission system was installed at Cerchi, Italy, 



150 H.P being transmitted for 17 miles at 2000 volts single phase. 



1887 Tesla, Ferraris and Bradley pointed out the advantages of the three- 



phase system. 



1888 Rotating field principle of alternating-current generators was invented. 



1889 The first A.C hydro-electric installation in the United States was 



installed by the Willamette Falls Electric Co., 300 H.P. being trans- 

 mitted for 13 miles at 4000 volts single phase. 



1891 Lauffen-Frankfort Transmission. 110 H.P. was transmitted from 

 Lauffen to the Exposition at Frankfort, a distance of 112 miles at 

 12,000 volts, three phase. 



1891 Sixty cycles introduced in United States. 



1892 The first long-distance transmission in United States at San Antonio, 



Cal. 800 H.P. was transmitted 28 miles at 10,000 volts single phase. 



1893 Twenty-five cycles introduced. 



1893 The first three-phase hydro-electric plant in United States was in- 

 stalled at Redlands, Cal. 



1895 The first 5000-H.P. generators were installed at the Niagara Falls 



Power Company. 



1896 25,000-volt system of the Pioneer Electric Power Company, Utah. 

 1903 60,000-volt system of the Guanajuato Power and Electric Co., Mexico. 

 1908 110,000-volt system of Au Sable Electric Company, Grand Rapids, 



Mich. 



1913 150,000-volt system of the Pacific Light and Power Co., Los Angeles, 

 Cal. 



