A Linrr vo tre Amsrtious. 419 
should be prevented from running up a stream beyond a cer- 
tain point; hence the following screen is intended to prevent 
them from leaping a small cascade. 
Tue HorizonraL SCREEN. 
This may be constructed of horizontal bars placed three 
inches apart, instead of lattice-work ; or it may be of copper 
wire. 
‘CHE CURRENT WHEEL. 
This wheel will prevent fish from passing up stream, while 
the horizontal sereen allows the passage of floating food. 
Concluding that enough information has been laid before 
the student for enabling him to begin fish-farming and pur- 
sue 1t with success, I will therefore proceed to another topic. 
