240 PRESSURE OF WATER. 



miles in thickness. That would give a pressure 

 of more than two tons on every square inch of the 

 solid nucleus, exclusive of the pressure of the at- 

 mosphere, or a pressure equal to the weight of 

 the whole navy of Great Britain on a surface 

 equal to the floor of an ordinary- sized room. 



When we reflect upon that immense resistance 

 of pressure, which the internal powers of the 

 earth that elevated the mountains had to over- 

 come, we may cease to wonder at the results that 

 have. been produced; nor need we be in the least 

 astonished, when we go to mountainous coun- 

 tries, and find strata of firm stone many miles in 

 extent and many fathoms in thickness, bent and 

 twisted as if they were pancakes, or turned on 

 their edges, as if they were ice -brash of but one 

 hour's formation before the roll of the ocean, or 

 the wing of the morning gale ; or when we find 

 granite moulded as if it had been dough. As 

 little need we wonder when we find a " dyke " of 

 different, or more modern formation, or a " lode " 

 of spar and metallic ore, cleaving sheer through 

 a mountain ridge, or extending many degrees on 

 the girdle of the earth. To a power that could 

 overcome such resistance we can set no bounds. 



But vast as that resistance is, when we bring 

 it to the test of numbers the only one by which 

 we can get an accurate judgment it is really no- 

 thing as compared with the resistance, farther 

 down ; for go but one-fourth of the distance to 

 the earth's centre, and the pressure on a single 

 inch would make the greatest mountain, nay, all 

 the land which stands out above the mean level of 

 the sea, kick the beam. 



Now, as we have stated the mean depth of the 



