Pioneer Laborers 21 



''union is strength," and they so constantly work in com- 

 pany that it is a difficult matter to apportion the results of 

 their labors exactly each to each. We have already seen 

 how water dissolves; we must now look at it in another 

 capacity, and see how it acts the part of crowbar and 

 pickaxe, and even at times of dynamite. A cubic inch of 

 water, when converted into steam, occupies just 1,728 

 times as much space as it did before, and it expands with 

 such violent force as to shatter the rocks beneath which it 

 is confined. Such explosions as this sometimes occur 

 during volcanic eruptions, water having found its way 

 down through the earth till it has come into contact with 

 some mass of molten lava, which has converted it into 

 steam, and made it a powerful engine of destruction. 

 But water expands also, though in a less degree, when it 

 is converted into ice, and it is under this aspect that we 

 are most famihar with its doings. 



Water, as we have said, finds entrance everywhere, 

 more or less, in one way or another, and wherever it is 

 sufficiently near the surface to freeze, there it has the 

 effect of a multitude of crowbars and chisels of all sorts 

 and sizes wielded by an invisible army of workmen. It 

 widens every crack in which it is formed, prizing up large 

 masses of rock many tons in weight, loosening and eventu- 

 ally forcing them off, and also doing finer work, such as 

 chiseling off splinters and particles of all sizes, large and 

 small. The immense piles of rubbish which strew the 

 surface of the glaciers, and consist of sand, grit, and 

 fragments of all dimensions, are due mainly to the action 

 of the frost, which in mountain regions recurs not merely 

 every winter, but every night throughout the year. 



But even where there is no rain, and no ice can there- 



