This is the "mountain-girdled Squam" of which Whittier sings, and a giant pine tree is pointed out on its banks where the poet used to sit and watch the lake by hours, and in honor of which he wrote the _Wood Giant_, one of his most admirable poems. The Pemigewasset joins the outlet stream of Lake Winnepesaukee at Franklin, and they together form the noble Merrimack, which, in its useful flow to the sea, turns so many New England mill-wheels. The Pemigewasset and its branches drain the southern slopes of the Franconia ranges in a vast primeval forest, whose inner solitudes are rarely explored. Upon its eastern verge, far up on the southwestern slope of Mount Willey, is Ethan's Pond, said to be the most elevated source of the Merrimack, twenty-five hundred feet above the sea. Its most remote source is the Profile Lake, at the head of the Pemigewasset, over which the "Great Stone Face" mounts guard. Thus writes Thoreau of the Merrimack: "At first it comes on, murmuring to itself, by the base of stately and retired mountains, through moist, primitive woods, whose juices it receives, where the bear still drinks it and the cabins of settlers are far between, and there are few to cross its stream; enjoying in solitude its cascades still unknown to fame; by long ranges of mountains of Sandwich and of Squam, slumbering like tumuli of Titans, with the peaks of Moosilauke, the Haystacks and Kearsarge reflected in its waters; where the maple and the raspberry, those lovers of the hills, flourish amid temperate dews; flowing long and full of meaning, but untranslatable as its name, Pemigewasset, by many a pastured Pelion and Ossa, where unnamed muses haunt, tended by Oreades, Dryads and Nereids, and receiving the tribute of many an untasted Hippocrene: "'Such water do the gods distil, And pour down every hill, For their New England men. A draught of this will nectar bring, And I'll not taste the spring Of Helicon again.' "Where it meets the sea is Plum Island, its sand ridges scalloping along the horizon like the sea-serpent, and its distant outline broken by many a tall ship, leaning, still, against the sky. Standing at its mouth, looking up its sparkling stream to its source,--a silver cascade which falls all the way from the White Mountains to the sea,--and behold a city on each successive plateau, a busy colony of human beavers around every fall. Not to mention Newburyport and Haverhill, see Lawrence and Lowell, and Nashua and Manchester and Concord, gleaming one above the other." THE WHITE MOUNTAIN NOTCH.