82 



THE SCIENCE OF DRY FLY FISHING. 



from the bottom of a well, the mouth of which subtends over 

 its head an arc of about half that in which these objects 

 really exist, and consequently, the comparative size of these 

 objects must be relatively smaller in view of their being 

 cramped into the smaller field of vision. 



In order to make this perfectly clear to my readers I have 



DIAGRAM 8. 



acbd, ABCD, surface of water. 

 E, the eye of trout. 



E A, E B, E C, E D, the upward cone within which is confined the trout's sight 

 of all objects above surface of the water within the range of the trout's vision. 



shown two diagrams. 



In Diagram 8 E is the eye of the fish, from which 

 rises a vertical cone E A, E C, E B, E D, the sides of which 

 cut the surface of the water as shown at A B C D. 



All rays of light from objects above the water which 

 reach the trout at E must enter the water within the circle 

 ACBD. Let A E B (see Diagram 9) be a vertical 



