226 



REPORT 1861. 



Table IV. — Experiments D, on Hard Quartz ; pressure 

 parallel to lamination. 



Hard 



Quartz. 



Table V. — Experiments E, on Soft Slate ; pressure 

 transverse to lamination. 



L_J 



Soft 



^ Slate. 



Note. — The cube E was 0693 inch on the side, and the necessary reductions have been 

 made in column 2 and subsequent ones. 



