Buck. — Controlling the Movements of Fish 145 



also for maintaining different water levels desired or for drawing down 

 the pond. A recess in the front side of the partition is provided to 

 admit a board, in sections, for closing the openings, thus effectually 

 preventing leakage. This method is recommended where it is neces- 

 sary to economize water. 



Professor Dyche: I do not know that I caught the first of Mr. 

 Brown's remarks, but these ponds are all connected one with the other 

 by cement runways in which flash-boards and wire screens can be 

 placed. The height of the water in any pond can be regulated by the 

 height of the flash-boards. There is a system of pipes for water supply 

 and drainage purposes, none of which are less than eight inches in 

 diameter; these pipes will carry the water into the drainage of waste 

 pipes and from pond to pond. 



The drainage pipes take the water from the cement basins and from 

 the deepest places between the ponds in the runways. One can see and 

 know what is there before the water is started through the drain. The 

 screens, when properly placed, will protect against the loss of any fish. 



It is possible to know the condition of things all the time, since all 

 these ponds are built independently of each other and can be so used 

 as independent ponds ; or they can be connected two or more together, 

 if so desired. 



