THE SPAWNING RACE. 63 



B, B, B, B the notched boards placed across the 

 race, at right angles to the natural current ; c, c, 

 c, c, c, c, c, c the notches through which the water 

 flows, the dotted line indicating the direction of 

 the current. It is thus readily seen that the fish, 

 on passing through the notch, at once finds him- 

 self in comparatively still water, and is thus able 

 to rest himself and prepare for his ascent to the 

 next pool. The boards may be held in place 

 by a few twenty-penny nails, driven into the ce- 

 ment between the bricks upon the lower side, the 

 force of the current retaining them well in their 

 places. 



Over the whole should be placed a cover. 

 Loose boards have been much used, but we have 

 objected to them from the time occupied in remov- 

 ing and replacing them. Covers formed of three- 

 eighth inch pine boards, well-nailed to battens 

 with wrought iron nails, and provided with hinges, 

 pulleys, and a counterpoise weight, can be made 

 to raise or lower at a touch. They are, it is 

 true, somewhat more expensive than old odds and 

 ends of hemlock boards, but when once made and 

 thoroughly painted, will, if put away carefully at 

 the end of the season, last a life-time. 



Having thus shown how the important requisites 

 of shade, gravel, and easy access are afforded our 

 fishes, we will next consider the four varieties 



