262 GEOGRAPHIC HISTOR Y OF PIEDMONT PLA TEA U 
river and elsewhere throughout the Piedmont province. So the 
brawling brooks and turbulent rivers declare that the Piedmont 
hills and valleys are slowly but incessantly wasting. 
Consider the ways in which the waters run : Some rivers flow 
sluggishly in broad, flat-bottomed valle}'s flanked by gentle 
slopes, but the Rivanna and all its feeders and neighbors rush 
through narrow, rock-bound gorges, and on reaching the coastal 
plain cascade over huge bowlders and rugged ledges down nearly 
or quite to tide-level. Now, swift-flowing waters cut their chan- 
nels quickly, and the fact that all the Piedmont rivers, large and 
small, are incessantly corrading their beds yet are unable to 
carve them down to tide-level, proves that the land is lifting. 
This is the second of the two starting ])oints in the reading of 
geographic history; he who would learn how continents come 
to be must realize that the earth-crust is ever warping, that all 
lands are slowl}’^ rising or sinking in some of their parts, and 
that streams are living witnesses of the movement — for without 
this realization he must needs linger at the threshold of knowl- 
edge, where the forefathers unwittingly loitered before geograjdiy 
became science, and leave to others thejo}" of full understanding. 
The rate of land-lifting has not been measured, but since even 
the strongest streams are unable to cut their narrow channels 
down to tide-level, the rate must be many times the mean sur- 
face waste. Probably the Piedmont is rising about as rapidly 
as the adjacent lowland is sinking, and this has been reckoned 
at two feet j)er centur}" in New Jersey, and may be one-third so 
much in Virginia. By reason of the land-lifting the modern 
Piedmont channels are carved sharply in the rock; these chan- 
nels are but the bottoms of sharp-cut gorges 100 to 300 feet deep 
(the trenches of the recently defined Ozarkian epoch), and thus 
the gorges indicate that the lifting of the Piedmont is not the 
movement of a day or millenium merely, but has continued 
through ages. So the rushing rivers and rugged riverways of 
the Piedmont declare that the province is now, and long has 
been, rising more rapidly than the hills and valleys are wasting. 
Consider ne.xt the parallel mountain ranges: Monticello and 
the rest of Carter mountain are but a ridge of hard rock scored 
b}’ ravines and thinly mantled with soil, and Ragged mountain 
on the west. Southwest mountain on the north, and all the other 
ranges diversifying the plateau are its counterparts. The moun- 
tains are ribbed with silicious schists or quartzites or other rocks 
that resist well the work of the weather, the beating of storms, 
