Fig. 6. 



Profile Curves. 

 from Fig. 1. 



■^■:77?r. 



x^ 



Redrawn Fig. 7. Showing a family of profile 



curves taken from an artificially 

 prepared surface of a pine 

 sample together with a family 

 of transverse profile curves de- 

 duced from them. 



Each of these diagrams is a little larger than \ full size. In the original 

 records the datum lines are 1 inch apart. 



