Page:Popular Science Monthly Volume 68.djvu/201

Rh the Ordovician to the Glacial epoch must be interpreted, if at all, by the structural and physiographic records. The Labradorean ice sheet was, however, of enormous importance. Its deposits are heavy, and it doubtless operated to form numberless lakes and to greatly reorganize the drainage, as will be later pointed out in a few suggestive instances.

The Mountains Proper and the Western Plateau.—The Adirondack region, sometimes referred to as the Great North Woods, is mountainous in its eastern half, and has its highest peaks near its center, but on the west the mountains disappear and the area becomes a plateau ranging from 2,000 feet above tide gradually downward to the west until it is but slightly higher than Lake Ontario and the St. Lawrence. The



loftiest peak is Marcy, 5,344 feet, and there are one or two others which exceed 5,000, together with five or six additional above 4,500, and many above 3.000. The mountains are ranged in visible northeast and southwest lines, and are often very steep if not positively precipitous in the portions that look to the southeast or northwest. There are also other steep faces nearly at right angles with the above, but they are less pronounced. When viewed from a distance the profile is strongly serrate—a gradual slope up on one side being cut off abruptly by an almost vertical descent on the other.

The individual mountains are diversified in shape. Mt. Marcy is a very low cone, and the last stages of its ascent are very much like climbing a dome. Mt. McIntyre has a gradual slope from the northwest,