was used in this experiment; structural details 

 were given by Collins, EUing, Gauley, and 

 Thompson (1963). 



A series of 16 boxlike pools formed the 

 fishway. Figures 2 and 3 show the helical ar- 

 rangement of the pools and details of con- 

 struction. All principal structures were of 

 wood, and except for the crests of weirs, all 

 interior surfaces were painted camouflage 

 brown. The surface of each weir crest was 

 painted white to aid in the observation of fish. 

 The weirs had no orifices, but a 5-cm. -diame- 

 ter hole was provided to permit drainage. 

 Crests of weirs were square and 5 cm. 

 thick. 



The connecting link of the l6-pool circuit 

 was the locking pool (pool 1). Fish could be 



lowered from the uppern-iost to the lowernnost 

 elevation to begin another ascentof the fishway 

 while a diffusion chamber built into the down- 

 stream end of the locking pool provided a con- 

 tinuous water supply for the fishway (fig. 2). 



Light conditions were constant. Thousand- 

 watt mercury- vapor lights placed 1.8 m. above 

 the water at 1.8-m. intervals throughout the 

 course of the fishway provided an average 

 light intensity of 800 foot-candles at the water 

 surface. 



The outer wall of pool 1 3 was faced with clear 

 plastic 19 mm. thick, to facilitate observation 

 (fig. 3). Other than during turbid conditions 

 (Secchi disc readings below 0.6 m.), most of 

 the pool area was visible under the prevailing 

 light and hydraulic conditions. 



OBSERVATION CHAMBER—' 



DIFFUSION CHAMBER 



DROPGATE- 

 LOCK- 

 ENTRANCE FISHWAY- 

 OVERFLOW SPILLOUT- 



ENTRY CHANNEL 



^L 



EXIT FISHWAY 



W 



!•■ 



SCALE 



METERS I I I I I I 

 5 



■DIRECTION OF MOVEMENT 

 OF FISH 



I— TO EXIT FISHWAY 



-BYPASS CHANNEL 

 FISHWAY ENTRY GATE 



'i ^INTRODUCTORY POOL GATE 

 RELEASE COMPARTMENT 

 INTRODUCTORY POOL 

 COLLECTION POOL 



Figure 2. — Plan view of the l-on-16 slope endless fish- 

 way with auxiliary approach channels and pools. 



