BULL. GEOL. SOC. AM. 



VOL. 22, 1910, PL. 11 



Figure 1. — .Joints widkxed at thk Surface through Solution by descending 



METEORIC Water 



In white crystalline limestone at Sheffield, Massachusetts. (Hohhs, U. S. Geological 



Survey. ) 



Figure 2. — Control of Drainage by .Joint I'lanes near Ithaca, New York 



(After a photograph by Tarr) 



CONTROL OF DIRECTION OF WATERWAYS IN HUMID REGIONS OF MODERATE LATITUDES 



