A Limit to the Ambitious. 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. 



The Hokizontal Scklen. 



This may be constructed of horizontal bars placed three 

 inches apart, instead of lattice-virork ; or it may be of copper 

 wire. 



The Cukrent Wheel. 



This wheel will prevent fish from passing up stream, while 

 the horizontal screen 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 it with success, I will therefore proceed to another topic. 



