GEOLOGY. 609 



tains issue from gorges of erosion. There are some which, 

 like the cascade of Taurus, spread out in large sheets at the 

 place where they fall ; others precipitate themselves in the 

 form of simple runlets of water from lofty heights, and fall 

 in vast basins at their foot, as in the Circus of Gavarnie ; 

 some spread themselves like a net-work of streams on a 

 gentle slope, and resemble a skein of white silk, whose sil- 

 very gleams undulate softly on the verdure of the hillocks. 

 Seen from a distance, one might say it was a tress of hair 

 agitated by a gentle wind. These are what the mountain- 

 eers, in their picturesque language, call the " Locks of the 

 Magdalen." 



A very remarkable cascade, perhaps the grandest moun- 

 tain waterfall in the known world, is that in Northern Cali- 

 fornia, called the Yosemite Falls. Experienced travellers 

 say that there are no precipices in Asia which, for height 

 and grandeur, can be compared with the vertical granite 

 walls of the Yosemite Valley. Standing on the verge of 

 one of these tremendous precipices, one may look down 

 more than three thousand feet, a distance which baffles the 

 eye and the mind to appreciate. By the most recent geo- 

 logical surveys the Yosemite Falls are credited with the as- 

 tounding height of 2800 feet. At an early period it is 

 probable that the entire mass of water plunged down that 

 distance without a break, but at the present time a single 

 ledge of slant projection changes the headlong flood from 

 cataract to rapids for about 400 feet, thus forming three 

 cascades. But the upper fall has an unbroken descent of 

 1500 feet, and the lower one of 1300. 



Instead of these mountain cascades, the variety of which 



