18 



HOW TO TIE FLIES. 



This last statement, "the advancing edge/' 

 &c., is all that I can find in Mr. WelFs discussion 

 by way of proof, that it is the upper surface of 

 the hook point (or, as Mr. Wells's calls it, "the 

 advancing edge"), which determines the direction 

 of penetration. If his experiments be carefully 

 performed, it will be seen that the under surface 



FIG. 6. The largest hook in the above diagram is referred 

 to by Mr. PenneU as " mechanically perfect so far as 

 penetration depending on bend is concerned." It is not 

 really so. The smaller figures illustrate such mechani- 

 cally perfect hooks out-barb and in-barb. The put-barb 

 hook in existence is the nearest approach obtainable to 

 the perfection of which Mr. Pennell speaks. 



(or " following edge ") has quite an equal in- 

 fluence, and that the line of penetration, as I 

 have already said, lies between the two surfaces. 

 The reason that the chisel does not bury in the 

 first experiment is because its point is not 

 " searching/' and is unable to insinuate itself be- 

 hind any of the minute roughness of the wood, 

 and so get a " catch on." The result would be 



