The Mighty Deep 



A much greater area of water than of land is 

 found upon the Earth's surface. So vast is the 

 amount of the former that, if the whole had to be 

 put into separate vessels, each vessel being one 

 cubic mile in size, the number of such vessels 

 required would amount to no less than three 

 hundred and thirty-five millions. This very 

 large order speaks for itself. 



The outer Crust of our Earth, taking land 

 and sea together, may be divided into three 

 distinct parts. Like most such divisions in 

 Nature, the one is often found to glide by 

 gentle stages into another. 



We have, first, Land, rising above the sea- 

 level, and consisting of plains, undulations, hills, 

 mountains. It covers altogether less than one- 

 third of the Earth's surface, and it is called 

 THE CONTINENTAL AREA, though Islands as well 

 as Continents belong to it. 



We have, secondly, the Ocean-floor under 

 deeper parts of the Ocean ; that which lies 

 beyond a depth of about two miles. This 

 division has been described as the " great sub- 

 merged plain," and it comprises about one-half 

 of the Earth's surface. It is known as THE 

 ABYSMAL AREA. 



We have, thirdly, a middle region, which may 



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