the latitude of southern New York the crystalline rocks are
compressed into narrow compass and lose their mountainous character.
They form the irregular hills on which New York City itself is built and
which make the suburbs of Westchester County along the eastern Hudson
so diverse and beautiful. To the southeast the topography of the old
crystalline band becomes still less pronounced, as may be seen in the
rolling, fertile hills around Philadelphia. Farther south the band
divides into two parts, the mountains proper and the Piedmont plateau.
The mountains begin at the Blue Ridge, which in Virginia raises its
even-topped heights mile after mile across the length of that State. In
North Carolina, however, they lose their character as a single ridge
and expand into the broad mass of the southern Appalachians. There Mount
Mitchell dominates the eastern part of the American continent and is
surrounded by over thirty other mountains rising to a height of at least
six thousand feet. The Piedmont plateau, which lies at the eastern foot
of the Blue Ridge, is not really a plateau but a peneplain or ancient
lowland worn almost to a plain. It expands to a width of one hundred
miles in Virginia and the Carolinas and forms the part of those States
where most of the larger towns are situated. Among its low gentle
heights there rises an occasional little monadnock like Chapel Hill,
where the University of North Carolina lies on a rugged eminence which
strikingly recalls New England. For the most part, however, the hills
of the Piedmont region are lower and more rounded than those in
the neighborhood of Philadelphia. The country thus formed has many
advantages, for it is flat enough to be used for agriculture and yet
varied enough to be free from the monotony of the level plains.

The prolonged and broken inner valley forming the second band of the
Appalachians was of some importance as a highway in the days of the
Indians. Today the main highways of traffic touch it only to cross it as
quickly as possible. From Lake Champlain it trends straight southward in
the Hudson Valley until the Catskills have been passed. Then, while the
railroads and all the traffic go on down the gorge of the Hudson to
New York, the valley swings off into Pennsylvania past Scranton,
Wilkesbarre, and Harrisburg. There the underlying rock consists of a
series of alternately hard and soft layers which have been crumpled up
much as one might wrinkle a rug with one