8 



GENERAL INTRODUCTION 



achievement and an indication of the possibilities of electric trans- 

 mission of power. 



To Southern California also belongs the distinction of having 

 the first commercial polyphase transmission system installed and 

 operated in the United States. In 1893 a generating station was 



150,000 

 140,000 

 130,000 

 120,000 

 110,000 



100,000 g 



3 



90,000 ^ 



80,000 

 



70,000 

 I 



60,000 

 50,000 

 40,000 

 30,000 

 20,000 

 10,000 



53 58 <- S3 55 o i-i a* co M< 



sinisssisii 



Yeac> 



FIG. 4. Commercial Transmission Voltages, 



built by the Redlands Electric Light & Power Company (now the 

 Southern California Edison Company), at the mouth of Mill 

 Creek Canyon. The plant consisted originally of two 250-Kw., 

 2400-volt, three-phase, Y-connected generators, running at 

 600 R.P.M., and driven by Pelton water wheels under a head of 

 295 feet. The power was transmitted for a distance of 1\ miles 



