34 MOUNTAIN AND MOORLAND 



Palma in the Canaries, and the Puy-de-D6me in 

 Auvergne. 



On the enormous heaps of debris which disfigure the 

 vicinity of smelting works, and better still in the 

 accumulations of rock dust around gold mines, one 

 may see the making of miniature gorges and valleys 

 under the influence of rain, frost, wind, and other 

 weathering agencies. The same sort of thing on a 

 large scale is going on around still active volcanoes, 

 but what is worn away and carried away is made good 

 again by fresh eruptions. When the volcano has been 

 long extinct the weathering has had time to tell, and it 

 may go so far that the volcanic nature of the moun- 

 tain is no longer very obvious. " In many cases," Pro- 

 fessor Geikie writes, "the cone-like form still persists, 

 although profoundly furrowed by innumerable gullies 

 and gorges ; in other cases the original symmetry has 

 entirely disappeared; while in yet others only a few 

 low hills, or merely a single abrupt knoll, may be left 

 to mark the site of a formerly extensive and lofty 

 mountain." 



Mount Rainier (or Tacoma), the highest mountain 

 in Washington State, rising to 14,444 feet, is an extinct 

 composite volcano, whichhas suffered great denudation. 

 It is now snow-capped and supports glaciers, but it is 

 still recognisable for what it is. But many others have 

 been worn away to their very roots. Not infrequently 

 there remains the plug of igneous rock that solidified 

 and choked the old neck or funnel of eruption, and 

 this stands out as a boss or tower a conspicuous 

 feature in the landscape. There are many of these 

 "necks" in Scotland, vestiges of very ancient 

 (Palaeozoic) volcanoes, such as Arthur's Seat near 



