174 



ROYAL SOCIETY OF CANADA 



down all other wheels within ten miles of it. To supply 3,000 horse 

 power from a steam plant requires about 6 tons of coal per hour calculat- 

 ing at the conservative figure of 4 lbs. per horse power per hour ! By 

 comparison with this the ice combatting plant shows great economy. 

 Fig. 12, the two cubes, serves to illustrate this point. 



Fig. 12. 



In Fig. 1:^ : — '' a '' represents the amount of coal consumed in 24 

 hours in order to keep a 3000 h. p. hydro-electric station free from frazil. 

 The coal consumed is 1 ton. 



" b " represents the amount of coal consumed in a 3000 h. p. steam 

 station in 24 hours. The coal consumed in the steam station amounts 

 to 144 tons. 



Some such arrangement as that shown in Fig. 11 has to be impro- 

 vised for plants already in operation, and this simple scheme has worked 

 very successfully. 



