PRIMARY AND SECONDARY POWER 



683 



TABLE LXIII 



POWER REQUIRED FOR MANUFACTURING 

 Based on 1909 U. S. Census 



Horse- power 



Required per 



$1000 Product. 



Horse-power 



Used per Person 



Engaged in 



Industry. 



Agricultural implements 0.69 



Automobiles . 30 



Boots and shoes 0.19 



Brick and tile 3 .68 



Cement 5.90 



Chemicals 1 .78 



Copper, tin and sheet-iron products 0.31 



Cotton goods 2 .07 



Electrical machinery. . 72 



Fertilizers . 62 



Flour and grist-mill products . 97 



Foundry and machine shops 0.71 



Manufactured ice 7 . 40 



Iron and steel, blast furnaces 3 . 00 



Iron and steel, rolling mills 2.13 



Leather, tanned, curried and finished . 45 



Lumber and timber 2 . 46 



Paper and wood pulp 4 . 88 



Printing and publishing . 40 



Packing houses 0.15 



Copper smelting and refining . 42 



Woolen, worsted and felt goods . 83 



Total, all industries 0.91 



PRIMARY AND SECONDARY POWER 



Many companies make two classes of contracts for power, 

 known as primary and secondary. Under the terms of primary 

 power it guarantees to supply the amount of power contracted 

 for continuously throughout the year, and it is evident that 

 the maximum amount of such power is limited by the minimum 

 stream-flow and can only be safely increased by providing water 

 storage or steam auxiliaries to augment the shortage during 

 low- water periods. 



The minimum flow of the stream to be used may be the abso- 



