ELECTRIC FISH SCREEN 



123 



3. The lines of electric-current flow must be parallel with the direction of the 

 water flow. (See figs. 10 and 12.) 



4. The voltage gradient in the electric field should be kept as uniform as prac- 

 tical by the selection of proper electrode sizes and spacing. (See figs. 13 to 21, 

 inclusive.) 



Fig. 18 



5. The voltage gradient must be suitable for the size fish to be protected. If 

 the fish to be protected vary greatly in length, it may be necessary to use a double 

 screen. (See equation on p. 107.) 



6. The spacing between electrodes in the rows is determined largely by the 

 opening desii-ed for d6bris to pass through. 



7. The spacing between rows of electrodes should be approximately 1.33 times 

 the spacing of the electrodes in the rows. 



