320 PHYSICAL GEOGRAPHY OF THE SEA, AND ITS METEOROLOGY. 



there. In the deep sea there are no abrading processes at work ; 

 neither frosts nor lains are felt there, and the iorce of gravitation 

 is so paralyzed there that it cannot use half its power, as on dry 

 land, in tearing the overhanging rock from the precipice and 

 casting it down into the valley Lelow. 



594. The offices of animalculce. — Hitherto we have, in imagina- 

 tion, been disposed to regard the waters of the sea as a great 

 cushion, placed between the air and the bottom of the ocean, 

 to protect and defend it from these abrading agencies of the atmo- 

 sphere. The geological clock ma}^ we thought, strike new 

 periods ; its hands may point to era after era ; but, so long as the 

 ocean remains in Its basin, so long as its bottom is covered with 

 blue water, so long must the deep furrows and strong contrasts 

 in the solid crust below stand out boldly, rugged, ragged, and 

 gTandly. Nothing can fill up the hollows there ; no agent now 

 at work, that we know of, can descend into its depths, and level 

 oif the floors of the sea. But it now seems that we forgot the 

 myriads of animalculas that make the surface of the sea sparkle 

 and glow with life : they are secreting from its surface solid 

 matter for the ver}^ purpose of filling up those cavities below. 

 These little marine insects build their habitations at the surface, 

 and when the}^ die, their remains, in vast multitudes, sink down 

 and settle upon the bottom. They are the atoms of which 

 mountains are formed — plains spread out. Our marl- beds, the 

 clay in our river-bottoms, lai-ge portions of many of the great 

 basins of the earth, even flint}^ rocks are composed of the remains 

 of just such little creatures as these, which the ingenuity of 

 Brooke has enabled us to fish up from the depth of neaiiy four 

 miles (two thousand feet) below the sea-level.* These Fora- 

 minifera, therefore, when living, may have been preparing the 

 ingredients for the fruitful soil of a land that some earthquake or 

 upheaval, in ages far away in the future, may be sent to cast up 

 from the bottom of the sea for man's use. 



595. The study of them p'ofitable. — The study of these "sunless 

 treasures," recovered with so much ingenuity from the rich 

 bottom of the sea, suggests new views concerning the physical 

 economy of the ocean. It not only leads us into the workshops 

 of the inhabitants of the sea— showing us through their nurseries 

 and cemeteries, and enabling us to stud}^ their econom}^ — but it 



* The greatest depth, from which specimens of bottom have been obtained, 

 is 19,800 feet (3300 fathoms) in the North Pacific. 



