262 OUR NATIONAL PARKS 



frightened, shouting, " A noble earthquake ! " 

 feeling sure I was going to learn something. 

 The shocks were so violent and varied, and suc- 

 ceeded one another so closely, one had to balance 

 in walking as if on the deck of a ship among the 

 waves, and it seemed impossible the high cliffs 

 should escape being shattered. In particular, I 

 feared that the sheer-fronted Sentinel Rock, 

 which rises to a height of three thousand feet, 

 would be shaken down, and I took shelter back 

 of a big pine, hoping I might be protected from 

 outbounding boulders, should any come so far. 

 I was now convinced that an earthquake had 

 been the maker of the taluses, and positive 

 proof soon came. It was a calm moonlight night, 

 and no sound was heard for the first minute or 

 two save a low muffled underground rumbling 

 and a slight rustling of the agitated trees, as if, 

 in wrestling with the mountains, Nature were 

 holding her breath. Then, suddenly, out of the 

 strange silence and strange motion there came a 

 tremendous roar. The Eagle Rock, a short dis- 

 tance up the valley, had given way, and I saw it 

 falling in thousands of the great boulders I had 

 been studying so long, pouring to the valley 

 floor in a free curve luminous from friction, 

 making a terribly sublime and beautiful spec- 

 tacle, — an arc of fire fifteen hundred feet span, 

 as true in form and as steady as a rainbow, in the 

 midst of the stupendous roaring rock storm. The 



