WORK OF GROUND-WATER 



-'.. , 



l'\K. -'(>. A sinkhole of recent development near Mcadc, Kan. (Johnson, U. S. 



licol. Surv.) 



Fit;. 27. South face of Landslip Mountain, Colo. The protruding mass on 

 Mic ri^ht has slumped down. (U. S. Geol. Surv.) 



