I050 



BULLETIN OF THE BUREAU OF FISHERIES. 

 III. THE COUNTERCURRENT SYSTEM. 



Figures 15 to 17 show the action of a twofold current, the parts opposing 

 each other and thereby retarding the velocity of the two combined. 





^^ 



/%7/7 



Fig. is. — McDonald. 



5ec//o/T^-B. 



lo/TC. 'Sec//on./frB:C.-/?. 



^^ 



/f— 



— B. 



G. 



P/an 



Fig. 16. — McDonald. 



In this fishway the water passes through a series of centrally located buckets inclined downstream into another 

 series of buckets located at either side of the fishway. provided on top with deflecting plates, whence it issues in an 

 upstream direction, opposinE the down current, as shown by arrows. The fishway may be protected by an iron grating 

 over which the fish ascend. 



