308 PHYSICAL GEOGRAPHY OF THE SEA, AND ITS METEOROLOGY. 



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

 sphere. The geological clock may, 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 grandly. 

 Nothing can fill up the hollows there ; no agent now at work, 

 that we know of, can descend into its depths, and level off the 

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

 animalculse that make the surface of the sea sparkle and glow 

 with life : they are secreting from its surface sohd matter for the 

 very purpose of filling up those cavities below. These little 

 marine insects build their habitations at the surface, and when they 

 die, their remains, in vast multitudes, sink do^vvTi 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, 

 large portions of many of the great basins of the earth, even flinty 

 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 nearly four miles (two thousand feet) below the 

 sea-level.* These Forayninifera, therefore, when Hving, may have 

 been preparing the ingredients for the fniitful 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 these "sunless treasures," recovered with so 

 The study of them much ingenuity from the rich bottom of the sea, 

 profitable. suggosts ucw ^dcws 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 ceme- 

 teries, and enabling us to study their economy, — but it conducts 

 us into the very chambers of the deep. Our investigations go to 

 show that the roaring waves and the mightiest billows of the 

 ocean repose, not upon hard or troubled beds, but upon cushions 

 of still water; that everywhere at the bottom of the deep sea 

 the solid ribs of the earth are protected, as with a garment, from 

 the abrading action of its currents, and that the cradle of its restless 

 waves is hned by a stratum" of water at rest, or so nearly at rest 

 that it can neither wear nor move the lightest bit of drift that 

 once lodges there. 



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

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



