THE SCIENCE OF CASTING A TROUT FLY 163 



The curves shown in Diagrams 9 and 12 made by the 

 rod point in the backward and forward casts are dissimilar. 



As the forearm is raised the elbow acts as a moving 

 pivot, and moves upward and forward, the shoulder thus 

 becoming a second pivot until the lifting movement of the 

 rod is converted into the backward action, at which moment 

 the pivotal action of the shoulder ceases, and the elbow 

 remains a stationary pivot during the rest of the backward 

 action (see Diagram 10). 



At the conclusion of the backward motion of the hand 

 and after the thumb has checked the rod, a slight raising 

 movement of the rod in the upward direction to which it is 



DIAGRAM 10. DIAGRAM n. 







Movements of the hand and elbow in the backward and forward casts. 



H. Hand. 

 E. Elbow. 



The reel, shown by circles, describes a spherical triangle, as shown in 

 Diagram 13, page 176. 



pointing gives a smooth effective finish to the back cast. 

 Quite apart from this optional movement, two different 

 curves will be made by the rod top in the back cast. In the 

 lifting movement the rod point describes a segment of an 

 ellipse with the shoulder and elbow as pivotal points, and in 

 the backward movement it describes the arc of a circle with 

 the elbow as pivot, the compound pivotal movement 

 resulting in two curves as shown in Diagram 10. 



In the forward and downward action of the rod one curve 

 only is made by the rod point ; the pivotal movements of 



