22 THE BOOK OF NATURE STUDY 



thief ? If the hill is not sufficiently extensive to afford an 

 example of a tiny stream, we can always go back in imagination 

 to the origin of the river, always suggest that it was born from the 

 clouds which formed round the peaks of the distant greater hills. 

 The air then carries the water from the river to the mountain, but 

 the mountain reclaims this water from the air, which it chills until 

 its grip relaxes, in order that it may give its own back to the 

 river. 



On the larger scale the same thing happens with the sea. The 

 river pours its water into the ocean. The air robs the ocean, but 

 as it flees ever farther and farther inland the mountains seize 

 its load and return it to the ocean. So the eternal struggle 

 goes on, while the impassive sun gazes on the combat which 

 he originates and controls, but the active part in which he leaves 

 to others. 



If the mountain gives back her own to the ocean, however, 

 it is not without paying a heavy price. With its cold fingers it 

 grasps the vapour borne by the air, but as if in revenge for being 

 brought back to earth that vapour makes streams which scar and 

 scour all the flanks of the mountain. Not the water only is 

 sent back to the river, but with it the very substance of the 

 mountain. With its water the river carries this down to the 

 sea ; and though the water returns, this load of sand and silt must 

 remain. As the struggle goes on the mountain loses more and 

 more, it gradually crumbles away, until in imagination we can 

 look forward to a period when it will have been worn so low that 

 it can no longer seize the floating vapour, and capture it for the 

 river. It is then that another party intervenes to redress the 

 inequality of the combat. The old earth awakes, shakes her- 

 self, pours back on the land the substances of which it has been 

 robbed, or raises bodily above sea-level the waste of the land 

 to make new mountain ranges and thus the eternal struggle 

 is renewed. Once again the mountain leagues itself with river 

 and sea to reclaim the load of vapour which the air would 

 capture. 



Something after this fashion would one wish to suggest the 

 basal facts of physical geography, long before the very name of 

 that science has been uttered. 



