Cm. XV.] 



FLOODS IN NORTH AMERICA. 



351 



the boundary cliffs of which have been thrown down by the 

 shock of an earthquake, or undermined by springs or other 



causes. 



Volumes might be filled with the enumeration of 



Although, there 



instances on record of these terrific catastrophes ; I shall 

 therefore select a few examples derived from regions which I 

 have myself visited. 



Two dry seasons in the White Mountains, in New Hamp- 

 shire (United States), were followed by heavy rains on the 

 28th August, 1826, when from the steep and lofty declivities 

 which rise abruptly on both sides of the river Saco, innumer- 

 able rocks and stones, many of sufficient size to fill a common 

 apartment, were detached, and in their descent swept down 

 before them, in one promiscuous and frightful ruin, forests, 

 shrubs, and the earth which sustained them, 

 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 after- 

 wards found to have slid three miles, with an average breadth 



of a quarter of a mile. The natural excavations commenced 

 generally in a trench a few yards in depth and a few rods in 

 width, and descended the mountains, widening and deepening 



till they became vast chasms. At the base of these hollow 

 ravines was seen a confused mass 



of ruins, consisting of 



transported earth, gravel, rocks, and trees. Forests of spruce- 

 fir and hemlock, a kind of fir somewhat resembling our yew 

 in foliage, were prostrated with as much ease as if they had 

 been fields of grain ; for, where they disputed the ground, 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 



