24 



GENERAL INTRODUCTION 



TABLE V 

 SUMMARY OF PRINCIPAL WATER POWERS CREATED BY BARGE CANAL l 



From Sixth Annual Report of N. Y. State Water Supply Commission. 



and interest charges upon both the aqueduct system and the 

 entire hydro-electric installation. 



PRIMARY POWER AND ITS USES 



Statistics have never been compiled giving accurately the 

 total mechanical horse-power used in the United States. The 

 following estimate may, however, be considered to be fairly close 

 to the actual conditions, and it is safe to place the present value 

 at approximately 180 million horse-power, or nearly two horse- 

 power per capita for the entire population. 



TABLE VI 

 PRIMARY POWER IN UNITED STATES 



Manufacturers 25,000,000 



Central, stations 8,500,000 



Isolated plants 4,500,000 



Street and electric railways 4,000,000 



Steam railroads 50,000,000 



Steam and naval vessels 5,000,000 



Mines and quarries 6,000,000 



Flour, grist and saw mills 1,500,000 



Irrigation 500,000 



Automobiles 50,000,000 



Horses and mules 25,000,000 



Total. 180,000,000 



