Figure 3. — Entrance to the fish collection pool. Fish swim into the laborotory 

 through a narrowing funnel that prevents them from leaving. 



Figure 4. — interior of Fisheries-Engineering Research Laboratory when empty and unwotered. 

 Experimental area (center) is 104 feet long, 24 feet wide, and 1 7 feet deep. Fish collec- 

 tion pool at far end is 50 feet long and 24 feet deep. 



