ROD TAPERS AND ROD PLOTTING 93 



tained. But a rod may be built on a swelled or con- 

 vex taper, that will have a superior action; and by 

 looking at the diagrams below, showing just what is 

 meant by a straight, a compound-straight, a concave, 

 and a convex taper, one will immediately recognize 

 that the lines of the latter are the same as those 

 which experience has proven most acceptable for 

 flagstaffs and ships' spars which also are subjected 

 to persistent bending strains. 



Whatever the style of taper of the rest of the rod, 

 in any event pattern the slender top-joint after the 



4C 



Different tapers: (i) Straight; (2) Compound straight or Scotch; 

 (3) Concave or hollow; (4) Convex or swelled 



lines suggested by Figures 2 or 4. It is very im- 

 portant for best results that the fullness at the butt 

 of the top-joint be carried well forward until about 

 the outer half of the joint is reached, when the cal- 

 iber may fall away pretty sharply from there on to 

 the very tip. As already mentioned, the extreme 

 outer end may be further or wholly so reduced with 

 sandpaper in the case especially of the finer tops 

 after gluing up. Other methods of accomplish- 

 ing a similar result will be noted later on. 



