

Template 



Contour -J 



"orthogonal line 



~~~<r^^-S/^ 



tongentto -^ ^ '^* 



mid-contour ( ^^-^'^'^ 



_-J^^_ /^^^" 



^0^'^'^ 



/ / \v 



incoming —) / 

 orthogonal C/ 



x. 



7 



turning ^ \. 

 point \ 



FIG. 2a -USE OF THE SMELL'S LAW TEMPLATE 



tongent to-^ 

 mid- contour^ 



mcomrng 

 orthogonal 



Note: The template hos been turned obout R until the value vq =i.045 



intersects the tangent to the mid- contour. The template "orthogonal" 

 line lies in the direction of the turned orthogonal. This direction is to 

 be laid off at some point "b" on the incoming orthogonal which is equi- 

 distant from the two contours along the incoming and outgoing orthogonols. 



FIG. 2b- USE OF THE SWELL'S LAW TEMPLATE 



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