

IB i i 



he 



'6 Of 



ii nut t. i : 

 iii. mil -r. i 



' 08 ' ' i . ' r ; , 1. :. . .\ . , ! . ; 



' . i i . i . ii>', . , : . . . . 



fcttf 



I (</) a romUerinmlr AK/. 



' 



imes the diameter ol the rivet, and iu height 

 meter of the rivet The conical head ha* a 

 id a height three quarters of the 

 mteat diameter of the pan bead is about 1*6. 

 the rivet diameter. The greatest diameter 

 head may be one and a half, and iU depth 

 ter of the rivet 



Int are shown geometrical constructions 



devised l*y tin- author for drawing the snap and conical head 

 for any size of rivet, the proportions being nearly the same at 

 those given al 



G'eomttrical Construction far Proportiomnff Snap Head*. 



With centre A, and radius equal to half diameter of rivet, 



describe a circle cutting the centre line of the rivet at B and C. 



ius BC describe the arc CD. Make 



1 > With centre E and radius ED describe the 



f nirf ion/or CWi/ J/md. \\ : i . . .-ntre K, and radius 

 equal to diameter of rivet, describe the semicircle LMN, cutting 

 the side of the rivet at M \\ >th centre M and radius MN 



