Two dry seasons in the White Mountains of New Hampshire were followed by heavy rains on August 28, 1826. From the steep and lofty slopes of the River Saco great masses of rock and stone were detached, and descending carried along with them “in one promiscuous and frightful ruin, forests, shrubs, and the earth which sustained them.” “Although there are numerous indications on the steep sides of these hills of former slides of the same kind, yet no tradition had been handed down of any similar catastrophe within the memory of man, and the growth of the forest on the very spots now devastated clearly showed that for a long interval nothing similar had occurred. One of these moving masses was afterwards found to have slid three miles, with an average breadth of a quarter of a mile.” At the base of the vast chasms formed by these natural excavations, a confused mass of ruins was seen, consisting of transported earth, gravel, rocks, and trees. Forests were prostrated with as much ease as if they had been mere fields of grain; if they resisted for a while, “the torrent of mud and rock accumulated behind till it gathered sufficient force to burst the temporary barrier.” “The valleys of the Amonoosuck and Saco presented, for many miles, an uninterrupted scene of desolation, all the bridges being carried away, as well as those over the tributary streams. In some places the road was excavated to the depth of from fifteen to twenty feet; in others it was covered with earth, rocks, and trees to as great a height. The water flowed for many weeks after the flood, as densely charged with earth as it could be without being changed into mud, and marks were seen in various localities of its having risen on either side of the valley to more than twenty-five feet above the ordinary level.” But perhaps the most remarkable evidence of the tremendous nature of this cataclysm is to be found in Lyell’s statements respecting the condition of the region nineteen years later. “I found the signs of devastation still very striking,” he says; “I also particularly remarked that the surface of the bare granite rocks had been smoothed by the passage over them of so much mud and stone.” Professor Hubbard mentions in _Silliman’s Journal_ that “in 1838 the deep channels worn by the avalanches of mud and stone, and the immense heaps of boulders and blocks of granite in the river channel, still formed a picturesque feature in the scenery.”