322 PHYSICAL GEOGRArHY OP THE SEA, AND ITS METEOROLOGY. 



an hour and even more. Every square foot of the earth's cnist 

 at the bottom of a four-knot current 3000 fathoms deep would 

 have no less than 506,880 — in round numbers, half a million — of 

 such columns of water daily dragging, and rubbing, and scouring, 

 and chafing over it, under a continuous pressure of 648 tons. 

 What would the bottom of the sea have to be made of to with- 

 stand such erosion ? AVater running with such a velocity, and 

 with the friction upon the bottom which such a pressure would 

 create, would in time wear away the thickest bed, though made 

 of the hardest adamant. Why, then, has not the bottom of the 

 sea been worn away ? Why have not its currents cut through 

 the solid crust in which its billows are rocked, and ripped 

 out from the bowels of the earth the masses of incandescent, 

 molten matter which geologists tell us lie pent up and boiling' 

 there ? 



598. Why they cannot chafe it. — If the currents of the sea, with 

 this four-mile velocity at the surface, and this hundreds of tons 

 pressure on the bottom, were permitted to chafe against its bed, 

 the Atlantic, instead of being two miles deep and 3000 miles 

 broad, would, we may imagine, have been long ago cut down into 

 a naiTow channel that might have been as the same ocean turned 

 up on edge, and measuring two miles broad and 3000 deep. But 

 had it been so cut, the proportion of land and water surface 

 would have been destroyed, and the winds, for lack of area to 

 play upon, could not have sucked up from the sea vapours for 

 the rains, and the face of the earth would have become as a 

 desert without water. Now there is a reason why such changes 

 should not take place, why the currents should not uproot nor 

 score the deep bed of the ocean, why they should not throw out 

 of adjustment any physical arrangement whatever: because, in 

 the presence of everlasting wisdom, a compass was set upon the face 

 of the deep ; because its imters tvere measured in the holloio of the 

 Almighty hand; because bars and doors ivere set to stay its proud 

 waves ; and because, when He gave to the sea His decree that its 

 icaters shoidd not pass His command. He laid the foundations of the 

 world so fast that they should not he removed for ever. 



599. WJiat it consists of. — By bringing up specimens from the 

 depth of the ocean, and studying them through the microscope, 

 it has been ascertained that the bed of the ocean is lined with 

 ihe microscopic remains of its own dead, with marine feculences 

 which lie on the bottom as lightly as gossamer. How frail yet 



