202 Mr. J. Boaz on the Structure 



one day or other come to their level, and again become the 

 play-ground of the little Nautilus. Such indeed are the 

 mighty revolutions which the crust of this earth has been sub- 

 jected to, that at vast depths we find the remains of tropical 

 animals and vegetables near the pole, and polar productions 

 near the equator. 



In endeavouring to account for these transitions phseno- 

 mena, philosophers have classed each other into Neptunians 

 and Plutonists. I will here briefly scan their respective doc- 

 trines. The former attribute all to the agency of water. There 

 is no doubt that by it the highest lands would, in the process 

 of future remote ages, find their way to the bottom of the sea 

 as mentioned above. But what of that ? Continuous silent 

 fritterings and wearings down might well reduce the height of 

 the Alps, so as to be washed by the waves of the ocean, and 

 indeed to level all distinctions between sea and land, but 

 could never remove "whole countries from one latitude or cli- 

 mate to another. On the other hand, the Plutonists attribute 

 all these phaenomena to internal fires and volcanic eruptions. 

 Although the effects of these are vast, and their potency ex- 

 tensive ; yet neither can they account for what have been pro- 

 duced. It is true we have seen mountains melted by internal 

 ignition, burst, and vomit their contents in rivers of liquid 

 lava to distant depots. Islands formed in the middle of the 

 sea, and immense beds of the hardest materials tossed up and 

 laid recumbent at every angle of elevation ; but still such gi- 

 gantic agency falls far short of placing the coast of Cayenne 

 at the pole, or Lapland at the equator; and yet there is a 

 natural power that can do this, other than any I have yet 

 mentioned; and that power is at this moment at work. 



The equatorial diameter of the globe is 8000 miles. It is 

 flattened at the poles like an orange. The proportion be- 

 tween the equatorial and polar diameters of the earth being 

 as 230 to 229 : hence the difference is a two hundred and 

 thirtieth part of the whole, or 35 miles. When therefore, in 

 the slow succession of ages, the polar parts of the earth be- 

 come the equatorial, either the solid parts at the present poles 

 must rise, or the hollows become filled up by the ocean, which 

 in that case will there have a depth equal to nearly 17 miles; 

 and, on the other hand, some parts of the present equatorial 

 terra Jirma, when wrought round to the situation of the future 

 poles, must so sink and accommodate themselves by centi'ifti- 

 gal action, and other gi'eat causes, as to cause the earth to as- 

 sume and maintain the form which it now has, — that of an ob- 

 late spheroid. 



I am not sure if this theory has ever been before suggested ; 



but 



