156 ACTION OF HEAT. 



as they are in their intensity, and majestic in their 

 effects, may have room and 'scope enough for mak^ 

 ing great mountains. 



It is true that considerable portions of matter are 

 thrown up at a few points by volcanoes on the land ; 

 but still it is doubtful whether any one mountain has 

 ever added permanently to its height by that means. 

 The present Vesuvius is to observation a volcanic 

 pile, but it is surrounded by the remains of a former 

 and loftiermountain, the summit of which has fallen 

 in after the former volcano has excavated the inte- 

 rior. We know, too, that when the connexion of 

 volcanoes with the sea is cut off, the volcanoes be-r 

 come still and cool by slow degrees. 



Thus we can see, as the power of heat has really 

 no material limit, how it can work, in successive 

 exhaustions and renovations, the continents and the 

 oceans, just as in revolving seasons it renews the 

 plants and the animals, and just as in the reciprocal 

 actions of containing vessels and contained fluids, it 

 repairs the waste of plants and animals by succes- 

 sive assimilations of nourishment. This heat, we 

 have already seen, is. even in the strength of its 

 working, not a thing that would measure one hair's 

 breadth by the scale, or cause the thousandth part 

 of the smallest grain to mount up on the balance ; 

 but still it can lay upon the whole globe, and all the 

 material works of the Creator, the gripe of a giant, 

 which nothing can resist, that before it the ancient 

 mountains are lighter than thistle-down, and the 

 fathomless strata of the earth itself are weaker than 

 cobwebs. What then shall we think of Him who 

 could with one word, or even without word or 

 wish, create this mighty energy, and send it down to 

 us in a garment as lovely as a sunbeam, and as gayly 

 tinted as a rainbow, and make it our best friend and 

 our most obedient servant, and, saving where im- 

 mortal spirit is concerned, make it throughout all 

 pature life itself 



