94 FLY FISHING AND SPINNING 



appearance is accompanied by an invariable agitation of the 

 surface, or the violent appearance of lines or flies over a 

 trout's head, even the most unsophisticated fish will quickly 

 learn to associate these two phenomena, and be increasingly 

 ready to take fright when a man is seen. Hence the 

 necessity for caution when approaching a fish, and delicacy 

 and finesse when casting on the part of the fisherman not 

 only on his own account, but out of consideration for his 

 brother anglers. The lifting of the line from the water 

 when making the backward cast should be effected in the 

 smoothest and the most delicate manner possible for the 

 latter reason. 



All other downward rays coming to the eye of the trout, 

 save those which enter the arc subtended by the cone of the 

 trout's vertical vision, are external to the cone, and are 

 either from the submerged portion of some floating object, 

 or the reflections from the under surface of the water of 

 sub-aqueous objects, the water, in this latter case, acting 

 outside this zone as a huge mirror of all bodies below its 

 surface (see E d D, E d D, Diagram 3). 



It must not be supposed that this mirror is an unbroken 

 one, for every object falling on and breaking the surface 

 of the water becomes at once visible, not only within the 

 zone A. C. B. D., Diagram 2, but outside this zone. This 

 is an important point, and is one which is but too often 

 over-looked by the fisherman. I have frequently met 

 people who imagine that, because they throw their line 

 so that it does not fall within the circle A. C. B. D., they are 

 by so doing preventing the trout from seeing it. When 

 coaching Major Sir William Evans Gordon, in 1909, I was 

 explaining the method of avoiding the drag by throwing 

 the line so that it fell in an up-stream curve on the water, 

 and he suggested the advantage that this cast would have 

 in presenting the fly to a trout immediately up-stream. He 



