Bul. 502, U. S. Dept. of Agriculture. PLATE IX. 
Fic. 1.—DRAINED SHALE LAND UNDER CULTIVATION. 
Fic. 2.—ALL THE IMPROVEMENTS SHOWN HAVE BEEN MADE SINCE A DRAINAGE SYSTEM 
WAS INSTALLED. 
RESULTS OF PROPERLY INSTALLED DRAINS ON SHALE LAND. 
