92 FLY FISHING AND SPINNING 



A C B D. Let A E B (see Diagram 3) be a vertical section 

 of the cone in Diagram 2, cutting the surface of the water at 

 A B. Then the rays of light from M N can only be seen by 

 a trout situated at E, when they enter along the dotted lines, 

 N B E, M b E, and the fish sees M N as in the direction b B, 

 and also relatively reduced in size to b B. 



Objects immediately over the trout will suffer least 

 from the influence of refraction, but their appearance will 

 suffer the more as they leave the zenith and approach the 

 hozizon. 



To the trout the full moon as it rises will appear as 

 a small horizontal line of light forty-two degrees above the 







DIAGRAM 2. 



a cb d, A B C D, surface of water ; 

 E, the eye of trout ; 



E A, E B, E C, ED, the upward cone within which is confined 

 the trout's sight of all objects above the surface of the 

 water within the range of the trout's vision. 



real horizon, and it will gradually assume its circular 

 shape as it approaches the zenith. 



It will thus be seen that the nearer an object is to the 

 water level when outside the water, the less will be the angle 

 which it will relatively subtend to the fish ; in other words, 

 the lower the position of an object when at equal distances, 

 the smaller it will appear to the fish. 



