Table 1. — Dimensions of fishways used in the slope 

 studies, July to September 1956. 



One-thousand-watt mercury -vapor 

 lamps suspended 6 feet above the water 

 provided light at an average intensity at the 

 surface of 700 foot candles and in a range 

 from 300 foot candles along the wall to 

 1000 foot candles directly under the lights. 



The head on the weirs, measured 4 

 feet upstream of the weir crests, was held 

 at 0.8 foot to maintain unifornn flow condi- 

 tions in both fishways. A greater head 

 tended to change the flow at the upper 

 weirs from plunging to streaming at un- 

 predictable times, which interrupted the 

 passage of fish (Elling and Raymond 1959). 



PROCEDURE 



TjT)es of Tests 



Two types of tests were made: one to 

 obtain passage times for individual fish and 

 the other to obtain a passage time for 

 groups of 20 fish. Only salmonids were 

 used for both tests, and only a single 

 species in group tests. 



Release of Fish 



After the fish entered the release com- 

 partment (figure 2) from the collection 



>> • 



Figure 2.- -Release compartment used to identify and release fish. 



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