Rod^moiking . 259 



so spaced, that the intervals between them constantly 

 and uniformly diminish from the butt to the tip. 



Now unite your rod and try it in every position, turn- 

 ing the several joints till you find that adjustment with 

 which the action is best. You will find it in that po- 

 sition in which the rod is most flexible, for all flexible 

 bodies tend to bend in the line of least resistance. 

 If you attempt to force it to bend otherwise by adjust- 

 ment of the rings, a compromise between the two, vary- 

 ing in proportion at different parts of the rod, will re- 

 sult, and the action of the rod will not be fair and true. 

 A glance will tell you whether the ferrules coincide with 

 the axis of the rod. If they do not, strive to find some 

 adjustment that will permit the crook to be set so that 

 it inclines upward. Having arranged this, look your rod 

 carefully over, and if you find any place where the grain 

 appears to run out to the surface, try to bring this on the 

 side, and not on the upper or under surface of the rod ; 

 for this indicates the natural line of cleavage, or tendency 

 to split. The cohesion between the fibres of the wood 

 here is much less than their tenacity ; or in other words, 

 it would require far less force to split the fibres apart 

 than to tear them asunder. When the rod is bent, the 

 upper surface, since it is the longer part of the curve, 

 must stretch, and the lower, for an analogous reason, 

 must condense somewhat. Under a heavy strain, if the 

 part in question were placed above or below, the fibres 

 would be apt to separate and slide over one another on this 

 line, or in other words split; whereas on the sides the 

 tendency to this is less, and the fibre must rather rupture 

 before the rod can give way. 



Having carefully studied all these points, avoiding 

 all the evils you can, and compromising with judgment 



