THE SCIENCE OF CASTING A TROUT FLY 177 



single handed rod, but also the movements made by the 

 upper hand on the salmon rod when making similar 

 casts. It will be seen that these movements form the 

 side of an inverted right angled spherical triangle, the 

 upward movement describing the perpendicular, the back- 

 ward movement the base, and the downward movement 

 the hypothenuse of such a triangle. 



