Mance: Quarry Industry of Southern Indiana 111 



Plot 7 is given to show the relative total cost of power with the different types 

 of tower plant equipment. This plot is the general summation of the data on power 

 costs that I have been able to collect. 



tion, as follows: (1) hydro-electric plants, (2) steam-electric 

 plants, (3) producer-gas electric plants. 



There is no question as to the low cost of power generated by 

 hydro-electric plants, but when the cost of transmission and the 



