ON THE DELUGE. 667 



tliat tidal oscillations,* combined with immense pressure, spread 

 and smoothed it, while in a rapidly cooling though viscous 

 state, over the surface of the land. 



The vast quantity of shingle, or rounded stones of all sizes, 

 may be accounted for in a manner unconnected with that of 

 water acting upon a shore ; though doubtless a great propor- 

 tion of the shingle we see has been rounded in that manner. 

 Melted stone, thrown out of a volcano, and propelled through 

 water with great velocity, might be rounded and cooled as shot 

 are when dropped into water from a tower. In modern volca- 

 noes we observe that some matter is thrown into the air, while 

 other, and the greater quantity, runs over the edges of a crater, 

 overflowing the adjacent tracts of land. 



Proceeding to the west coast of South America, we find that 

 near Concepcion there are beds of marine shells at a great height 

 above the level of the sea. These, say geologists, were once 

 under the ocean, but, in consequence of the gradual upheaval 

 of the land, are now far above it. They are closely com- 

 pressed together, and some are broken, though of a very solid 

 and durable nature ; and being near the surface of the land are 

 covered with only a thin stratum of earth. They are massed 

 together in a manner totally different from any in. which they 

 could have grown, therefore the argument used in Patagonia 

 is again applicable here. But in addition to this, there is 

 another fact deserving attention : namely, that there are similar 

 beds of similar shells, (identical with living species) about, 

 or rather below the level of the present ocean, and at some 

 distance from it.-f- 



In crossing the Cordillera of the Andes Mr. Darwin found 

 petrified trees, embedded in sandstone, six or seven thousand 

 feet above the level of the sea : and at twelve or thirteen thou- 

 sand feet above the sea-level he found fossil sea-shells, lime- 

 stone, sandstone, and a conglomerate in which were pebbles of 

 the " rock with shells."" Above the sandstone in which the petri- 

 fied trees were found, is " a great bed, apparently about one 

 thousand feet thick, of black augitic lava; and over this there 

 * Sec remarks on tides in the Appendix. t Pafjes 421, 2, 3. 



