242 TRAVELS THROUGH NORTH AMERICA: 
and Shenandoah ever rose during a flood, & 
common circumstance in spring and autumn, 
only equally high with what James River did 
in 1795, that is, fifteen feet above their usual 
level, such a circumstance might have occa¬ 
sioned a very material alteration in the ap¬ 
pearance of the gap. 
The Blue Ridge, on each side of the Pa- 
towmac, is formed, from the foundation to the 
summit, of large rocks deposited in beds of 
rich soft earth. This earth is very readily 
washed away, and in that case the rocks con¬ 
sequently become loose; indeed, they are fre¬ 
quently loosened even by heavy showers of 
rain. A proof of this came within my own 
observation, which I shall never forget. It 
had been raining excessively hard the whole 
morning of that day on which I arrived at 
this place ; the evening" however was very fine, 
and being anxious to behold the scene in every 
point of view, I crossed the river, and ascend¬ 
ed the mountain at a steep part on the op¬ 
posite side, where there was no path, and many 
large projecting rocks. I had walked up 
about fifty yards, when a large stone that I 
set my foot upon, and which appeared to me 
perfectly firm, all at once gave way; it had 
been loosened by the rain, and brought dow n 
such a heap of others with it in its fall, with 
such a tremendous noise at the same time. 
