Casting the Fly. 341 



trout captured in such water, will be found to have taken 

 the fly after it has been moved from the place where it 

 first fell. It is also true that in such water some demon- 

 stration on the part of the angler is usually necessary to 

 fasten the hook after the fly has been taken, or it will 

 be rejected and the opportunity lost ; also that the in- 

 terval during which this may successfully be done is 

 brief. 



Now it is mathematically certain that when the rod is 

 at a right angle with the line, a given movement of the 

 tip of the rod will transmit its impulse with the greatest 

 rapidity, and with the maximum of effect, through the 

 line, since then there is the least possible lost motion. 

 It is also certain that when the rod and line form one 

 straight line, a very considerable upward movement of 

 the tip is followed by but slight retraction of the line ; 

 there is then much lost motion, and consequently the 

 impulse is tardily conveyed to the hook. 



It is equally indisputable that when the rod is so 

 raised that the line is parallel with it, or nearly so, all 

 command over the former is gone ; the rod has already 

 shortened the line all it possibly can, and the power to 

 strike is lost. 



The problem is a most simple one. 



Let us suppose the tip of the rod to be pointing at an 

 object exactly forty feet distant from it. Now suppose 

 the tip to be raised three feet, the end describing in so 

 doing the arc of a circle of which the hand is the centre, 

 as in actual fishing. Clearly, now, that end is more dis- 

 tant from the assumed point than before, and more line 

 would be required to reach it ; or, in other words, the 

 line, if it did not break, must either stretch or move that 

 difference. Thus a theoretical measure of the efficiency 



