Figure 4. — Plexiglass window for viewing fish as they entered the 0.6-m.-diameter 

 pipe, 1964. One of the 180° turns is shown on right. 



Flow introduction 

 pool 

 Exit weirs 



0.6 m. -diameter pipe 



Luminescent 

 light panel 



Fish detectors 

 Introductory pool 



0.3 m.-diometer pipe 



Collection pool 



Figure 5. — Plan of the 0.3- and 0.6-m.-dlameter pipes, showing the release box and hydroscopes where fish passage 

 was recorded and locations of electronic detectors, interior pipe lamps, and truncated entrance cones, 1964. 



