2(54 GEOGRAPHIC HISTOR Y OF PIEDMONT PL A TEA U 
measured in the province, it may be determined roughly from 
the neighboring Appalachian province, where the sedimentary 
strata are corrugated as by compression from southeast to north- 
west into long ranges trending parallel with the provinces, and 
where the rocks are so little altered that their thickness may be 
measured accurately. The two provinces are closely related, 
differing chiefly in the greater compression suffered by the Pied- 
mont rocks ; and frequently in the mountain ])rovince, as always 
in the Piedmont, the strata expose planed edges. Now the planed 
A])palachian strata are three miles or more in vertical thickness, 
demonstrating that so much of rock matter has been carried 
away; and while the Piedmont waste may have been somewhat 
greater or a trifle less, all authorities are agreed that at least one 
and probably three or more vertical miles of rock matter have 
gone into the sea. The evidence of the two provinces is cor- 
roborated by that of a third ; for the coastal plain, to a width of 
some hundred miles and a depth of some thousand feet, is built 
of sediments demonstrably derived from the lost mountains. 
The time required for the paring down and bearing away of this 
immense mass of rock at the known rate of an inch in three 
centuries, or at any other conceivable rate, is vast, so vast as to 
tax the mind; yet he who falters at accepting the facts of mass 
or time only confesses failure to grasp this and other problems 
of modern geography. So the Piedmont rocks attest that the 
])i’ovince is but the foundation of a range, say 75 miles wide and 
3 miles high ; and the rivers and the rocks declare with one voice 
that this vast volume has been swept into the sea to build another 
province. This story of the moving of mountains is striking : 
Colorado canyon is sometimes regarded as the world’s most im- 
pressive exam})le of the w'ork of rain and river, yet the Piedmont 
is still more impressive ; for the James and Potomac and Susque- 
hanna must have traversed the ancient range in gorges no less 
profound than the Grand canyon, yet the storms and tributary 
streams stayed not when the canyons were cut, but continued 
consuming the can}mn walls until the}^ were gone, even until 
the mountains were not — the Colorado has cut a trench, the 
Piedmont rivers have carved a province. 
Thus the fertile plain of the Piedmont, the transverse river- 
ways, the parallel ranges, the subsoil rocks, teem with history 
which he who tarries a little may clearly read ; they tell that the 
land is wasting into the sea at measured rate, yet that in the 
present epoch the land-mass is lifting still more rapidly; they 
