The great Appalachian mountain system, divided into numberless ranges, extends along from fifty to one hundred and fifty miles inland parallel with the Atlantic coast line from the Gulf of St. Lawrence on the north to the Gulf of Mexico on the south. Between the city of Troy and the Atlantic seaboard the mighty-chasm Of the Lower Hudson breaks through this great Appalachian mountain system and rends its towering masses in twain from top to bottom. Up through this chasm the ocean's tide ebbs and ?ows through the river's channel, here, as it were, an arm of the Sea, for the distance of one hundred and fifty miles until its waves almost wash the foothills Of the Adirondacks.