UNIV THE OLD NORTHWEST. I. NORTH AMERICA IN OUTLINE. NORTH AMERICA is easily separable into three very plainly marked physical divisions. The Pacific Highlands, which are a vast plateau surmounted by the Rocky and Sierra Nevada Mountain systems, extend from the Arctic Ocean to the Isthmus of Panama, and form the primary feature of the continent. The Atlantic Highlands, consisting of the Labrador Plateau and the Appalachian Mountain system, with the adjacent eastern slope, extend from Labrador almost to the Gulf of Mexico, and form the secondary feature. Between the Pacific Highlands and the Atlantic Highlands, extending from the southern Gulf to the northern Ocean, 5,000 miles in length by 2,000 in breadth at the widest part, and opening out like a fan to the north, is the Central Plain. The Central Plain is also easily separable into three parts. First, the Arctic Plain descends by easy slopes from the wavy elevation called the Height of Land, north and northeast to the Arctic Ocean and Hudson Bay. Secondly, south of the Height of Land and a second similar elevation that takes off from it, near the head of Lake Superior, and sweeps southeast and northeast until it unites with the Appalachian Mountains in Northern New York, the Mississippi Valley falls away gently to the Gulf of Mexico. Thirdly, between the Arctic Plain and the Mississippi Valley lies the Basin of the Great Lakes, that is lengthened eastward in the St. Lawrence Valley. The two sides of the continent, as divided by the eastern ranges of the Rocky Mountains, present the strongest contrasts. The western side consists of great mountain chains, attaining high elevations, with short and abrupt descents to the Pacific Ocean; the eastern side is a vast plain, descending to the Arctic and Atlantic Oceans and the Gulf of Mexico, by long and easy lines, save in the southeast, where it is. interrupted by the moderate elevation of the Appalachian Mountains. Straight lines can be drawn from the Arctic Ocean to the Gulf of Mexico, from the southern shore of Lake Ontario to the Rio Grande, and from the source of the Ohio to the source of the Kansas, that will at no point rise 2,000 feet above the level of the sea. In fact, the geographer passes over whole States without finding any elevations of surface that he need represent upon a map intended for common purposes. On the one side, and particularly south of 49° north latitude, the coast line is remarkably regular; on the other side, remarkably irregular. On the west, few rivers descend to the sea, and not one of these cuts through the mountain masses and reaches the interior; on the east, every subdivision of the Central Plain is traversed by a great natural water-way. Hudson Strait, Hudson Bay, and the Nelson-Winnipeg River system together reach the very foot-hills of the Rocky Mountains. The noble St. Lawrence, cutting through the Appalachian Mountains, opens a channel for the Great Lakes to discharge their floods, and for man to ascend to the central parts of the continent. The Mississippi-Father of Waters—with his 35,000 miles of navigable affluents, gives ready means of access to every part of the great valley that bears his name. If three men should ascend these three water-ways to their farthest sources, they would find themselves in the heart of North America, and, so to speak, within a stone's-throw of one. another. One of these water-ways has played hitherto no considerable part in the affairs of civilized men; but the |