The South Mountain, an irregular and in some parts broken-down ridge, is the outpost of the Alleghenies, while the great Blue Ridge is their eastern buttress. The latter is about twenty miles northwest of the South Mountain, and is the famous Kittatinny range, named by the Indians, and in their figurative language meaning "the endless chain of hills." It stretches from the Catskills in New York southwest to Alabama, a distance of eight hundred miles, a veritable backbone for the Atlantic seaboard, its rounded ridgy peaks rising sometimes twenty-five hundred feet north of the Carolinas, and much higher in those States. It stands up like a great blue wall against the northwestern horizon, deeply notched where the rivers flow out, and is the eastern border for the mountain chain of numerous parallel ridges of varying heights and characteristics that stretch in rows behind it, covering a width of a hundred miles or more. Within this chain is the vast store of minerals that has done so much to create American wealth--the coal and iron, the ores and metals, that are in exhaustless supply, and upon the surface grew the forests of timber that were used in building the seaboard cities, but are now nearly all cut off. The great Atlantic Coast rivers rise among these mountain ridges, break through the Kittatinny and flow down to the ocean, while the streams on their western slopes drain into the Mississippi Valley. The Hudson breaks through the Kittatinny outcrop at the West Point Highlands, the Delaware forces a passage at the Water Gap, the Lehigh at the Lehigh Gap, below Mauch Chunk; the Schuylkill at Port Clinton, the Susquehanna at Dauphin, above Harrisburg, and the Potomac at Harper's Ferry. All these rivers either rise among or force their winding passages through the various ranges behind the great Blue Ridge, and also through the South Mountain and the successive parallel ranges of lower hills that are met on their way to the coast, so that all in their courses display most picturesque valleys. HARPER'S FERRY AND JOHN BROWN.