368 THE WORLD OF LIFE CHAP, xvm 



everywhere at great altitudes, snowfields and permanent 

 glaciers are formed, which not only carry down enormous 

 quantities of debris on their surfaces or embedded in their 

 substance, but with the help of that which is carried along 

 the valley-floors they rest on, and by the enormous weight 

 of the ice itself often miles in thickness, grind out deep 

 valleys and lake-basins before cosmic or other agencies cause 

 them to melt away. 



This continuous water-action goes on perpetually in 

 every continent, and is the great agent in producing that 

 infinite variety of contour of the land surface level plains, 

 gentle slopes, beautifully rounded downs, wave-like undula- 

 tions, valleys in every possible variety, basin-shaped, trough- 

 shaped, bounded by smooth slopes or rugged precipices, 

 straight or winding, and often leading us up into the very 

 heart of grand mountain scenery, with their domes and 

 ridges and rocky peaks, their swift-flowing streams, rushing 

 torrents, dark ravines, and glorious cascades, in endless 

 variety, beauty, and grandeur. 



And all this we owe to what are termed the " properties 

 of water," that extremely simple and unappreciated element, 

 which still abounds in mysteries that puzzle the men of 

 science. Without water in all its various forms and with 

 its many useful but very familiar properties, not only would 

 life on the earth be impossible, but unless it had existed in 

 the vast profusion of our ocean depths, and been endowed 

 with its less familiar powers and forces, the whole world, 

 instead of being a constantly varying scene of beauty a 

 very garden of delights for the delectation of all the higher 

 faculties of man, would have been for the most part a 

 scene of horror, perhaps the sport of volcanic agencies of 

 disruption and upheaval only modified by the disintegrating 

 effects of sun and wind action. 



Our earth might thus have been in a state not very 

 dissimilar from that in which the moon appears to be ; not 

 perhaps without a considerable amount of life, but with little 

 of its variety, and with hardly any of that exquisite charm 

 of contour and vegetation which we are now only beginning 

 to appreciate and to enjoy. 



