116 



BULLETIN OF THE BUREAU OF FISHERIES 



from which the fish -were to be protected. The water flow in the two paths was 

 adjusted to the desired value by regiilatuig the water level in pond No. 15 with stop 

 boards at the discharge into pond No. 16. The flow of water through the electrically 

 screened channel purposely was made 39 per cent higher than through the open chan- 

 nel, because it was thought that would make protection more difficult on account of 



ARRANGEHENT CF PCWDS AMD SCREEN 



FOR. 



EiXCTRIC FISH SCRECN TEST 



AT 



eONNEVfLLE FJSH HATCHEJW 



o 10 eo 3o '40 so 



I.I.I 



FEET 



FiQ. 11 



the inclination of the fish to follow the maximum water flow. A wire screen was in- 

 stalled in the west outlet of pond No. 12 to prevent the fish that went through the 

 electric screen into the protected area from escaping into pond No. 16. This screen 

 made it possible to check the effectiveness of the electric screen. The 15,000 

 chinook-salmon fingerlings used in the experiment had been reared in pond No. 12 



