ROD TAPERS AND ROD PLOTTING 95 



cross-sections marked respectively I, 2, 3, 4 feet, 

 etc., from the butt end. 



Next we must get the diameters of the respective 

 ends of our middle-joint, the rod being composed of 

 three joints or pieces; and for the reason that we 

 prefer all three completed joints to be of the same 

 length, and because allowance must be made for the 

 ferrule lengths, this is not so absolutely simple as it 

 might seem. For perfect accuracy in our figures 

 certain ferrule kngths must be known before we can 

 ascertain the diameters of the joints at the points 

 where the selected ferrules are to be located. 



The butt male (inner or center) ferrule of the 

 middle-joint will be seated about i/4 inches in the 

 female or outer ferrule at the smaller end of the 

 butt-joint, and the top-joint ferrule will seat about 

 i l /s inches in its companion half; thus the total length 

 of the rod when jointed up will be 2% inches shorter 

 than the total length of its three joints or parts if 

 placed simply end to end, without engaging the fer- 

 rules. We want a total length, jointed, of ten feet 

 or 1 20 inches; then we must have a total length, un- 

 jointed, of 122.375 inches, to be divided equally into 

 three parts. This gives 40.79 inches for each com- 

 pleted joint, including the projecting ferrules. The 

 female or projecting ferrule of the first- or butt-joint 

 reaching i/4 inches (the depth that the male half 

 seats) beyond the wood, gives 40.79 less i%, or 

 39.54 inches, for the actual wood length of that 



