NATURE IN MOTION. 35 



yielded, and rose to a lofty height. Every age has seen 

 huge rocks and large mountains appear thus unexpectedly 

 on the surface of the globe. In the last century, the 

 volcano of Jorullo rose, in Mexico, 1580 feet above the 

 surrounding plain*. The sea, also, has its volcanic moun- 

 tains, which are of a sudden thrown up from the bottom. 

 The famous island of Santorin, in 1810 still considerably 

 below the surface, was in 1830 only a few feet from it. 

 It appeared as an enormous peak, steep on all sides, but, 

 on the top, presenting the crater of a sub-marine volcano. 

 The igneous nature of the land below is strongly shown 

 by sulphuric vapors, which rise so actively, that ships now 

 anchor there in order to clean their copper thoroughly 

 and quickly. Stromboli, also, was, in like manner, sent 

 up from the deep, to take its place among the islands 

 of the Mediterranean; and, although Italy is now com- 

 paratively quiet, still its volcanoes pour forth inexhaustible 

 showers of burning matter, and temporary islands start up 

 now and then from the surrounding sea. 



Tremendous in their birth, and gigantic in their effect, 

 these sudden outbreaks can yet not compare, in their 

 permanent importance, with the quiet and almost imper 

 ceptible migration of small particles of sand and gravel. 

 Large granite blocks and masses of sandstone, high on 

 lofty mountain tops, are exposed to the varying influence 

 of heat and cold, rain and snow, and crumble, gradually, 

 into coarse-grained sand. Wind and weather, clouds and 

 springs, carry this down, where the restless waves of rivers 

 and streams seize it and hurry it on, through vale and 

 valley, on their long journey, until, at last, they reach 



