THE SENSES OF A TROUT 



93 



THESE FACTORS AS THEY AFFECT THE FISHERMAN 



This important fact is taken advantage of by the fisher- 

 man, who, although he may not understand the optical 

 laws of refraction, has learnt from experience that, in order 

 to avoid scaring the fish, he must crouch as much as possible 

 and thus reduce his height, and that an overhead cast is 

 more likely to scare a fish than a side cast. Not that he 

 escapes being seen when within the limit of the trout's 

 vision, but his bulk and that of his rod are then generally 



DIAGRAM 3. 

 A E B, a vertical section of the hollow cone in Diagram 2, 



cutting surface of water at A B. 

 M N, any object on land, such as a man. 

 E b M, E B N, the lines along which the rays of light from 



the man M N will travel to the fish. 



E b, E B, the direction in which the trout will see the man. 

 E d D, E d D, the lines showing how the under surface of 



water acts as a mirror to the trout of all objects under 



the water and outside the cone E A E B. 



insufficient to frighten the fish seriously. Wading is for 

 this reason the best method of approaching fish. Although 

 a man's size is relatively reduced the more nearly he sinks 

 to the level of the water, still, in ordinary circumstances, 

 he is clearly visible on the trout's horizon when within 

 that part of the zone D A B C, Diagram 1. If, then, this 



