PLAIN STAIRS FOE SHORT RISES. 



415 



THE SLIGO SALMON-STAIRS. 



These stairs, of heavy timbers and mason-work, are intend- 

 ed to assist salmon and trout up small natural falls or dams, 

 and for such object are highly successful. A dam may be 

 necessary across the stream a few rods below, so as to deepen 

 the water below the fall, and give the fish a swimming start. 

 The height of this sub-dam should be three feet, and the 

 whole work well considered, and designed with much atten- 

 tion to the gradient, depth of water, and place for the foot of 

 the ladder. 



The most important American ladder is the one adopted 

 by the Dominion of Canada, a sketch of which will be found 

 on the following page. 



