[CHAPTER XVI.]
ALPINE AND ARCTIC PLANTS IN CONNECTION WITH GEOLOGICAL HISTORY.
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The group of the White Mountains is the culminating point of the northern division of the great Appalachian range, extending from Tennessee to Gaspé in a south-west and north-east direction, and constituting the breast bone of the North American continent. This great ridge or succession of ridges has its highest peaks near its southern extremity, in the Black Mountains; but these are little higher than their northern rivals, which at least hold the undisputed distinction of being the highest hills in north-eastern America. As Guyot[189] has well remarked, the White Mountains do not occur in the general line of the chain, but rather on its eastern side. The central point of the range, represented by the Green Mountains and their continuation, describes a great curve from Gaspé to the valley of the Hudson, and opposite the middle of the concave side of this curved line towers the almost isolated group of the White Hills. On the other side is the narrow valley of Lake Champlain, and beyond this the great isolated mass of the Adirondack Mountains, nearly approaching in the altitude of their highest peaks, and greatly exceeding in their geological age, the opposite White Mountain group. The Appalachian range is thus, in this part of its course, supported on either side by outliers higher than itself. The dense grouping of mountains in this region is due to the resistance offered by the old Adirondack mass to the westward thrust of the Atlantic and the subsequent piling up against this mass of the ridges of palæozoic sediments. Southward of this the Atlantic thrust has driven these ridges back in a great bend to the westward.
[189] Silliman's Journal.
My present purpose is not to give a general geographical or geological sketch of the White Mountains, but to direct attention to the vegetation which clothes their summits, and its relation to the history of the mountains themselves. For this purpose I may first shortly describe the appearances presented in ascending the highest of them, Mount Washington, and then turn to the special points to which these notes relate.
In approaching Mount Washington by the Grand Trunk Railway, the traveller has ascended from the valley of the St. Lawrence to a height of 802 feet at the Alpine House at Gorham. Thence, in a distance of about eight miles along the bank of the Peabody River, to the Glen House, he ascends to the elevation of 1,632 feet above the sea; and it is here, or immediately opposite the Glen House, that the actual ascent begins. The distance from the Peabody River, opposite the hotel, to the summit is nine miles, and in this distance we ascend 4,656 feet, the total height being 6,288 feet above the sea.[190] Formerly only a bridle path led up this ascent; but now access can be had to the summit by carriage roads and by rail.
[190] According to Guyot, but some recent surveys make it a little higher.
These royal roads to the summit are, however, too democratic for the taste of some visitors, who mourn the olden days of ponies, guides and adventures; and though they give an excellent view of the geological structure of the mountain, they do not afford a good opportunity for the study of the alpine flora, which is one of the chief attractions of Mount Washington. For this reason, though I availed myself of the new road for gaining a general idea of the features of the group, I determined to ascend by Tuckerman's Ravine, a great chasm in the mountain side, named in honour of the indefatigable botanist of the North American lichens.[191] I was aided in this by the kindness of a gentleman of Boston, well acquainted with these hills, and passionately fond of their scenery.[192] Our party, in addition to this gentleman and myself, consisted of two ladies, two children, and two experienced guides, whose services were of the utmost importance, not only in indicating the path, but in removing windfalls and other obstructions, and in assisting members of the party over difficult and dangerous places.