All the stratified rocks of New- York, like those of other 

 countries, are the product of the sea. All these vast beds of 

 sandstone, slate, and limestone, were once deposited from the 

 waters of an ocean, which bore their materials either in chemical 

 solution, or mechanically suspended in the form of fine sediment. 

 The petrified shells, fishes, plants and similar objects which are 

 so commonly found in the rocky layers, are the remains of organic 

 things which either lived in the waters from which the rocks 

 were deposited, or which were washed into them from adjoining 

 shores. Therefore, we have in these remains specimens of the 

 animated population or of the vegetation of earth and sea, which 

 lived when these rocks were deposited. This is the great lesson 

 of all historic geology ; and to make it more clear, let us look at 

 the processes which are daily going on under our own observa- 

 tion. 



The rain which falls on our hills or plains, slowly, but surely 

 wears away their substance. The waters run from every slope, 

 or rise from every spring, loaded with particles of the earth ; 

 either dissolved in a limpid stream, or suspended in a turbid tor- 

 rent. The process is slow indeed ; so slow, that our brief obser- 

 vation can detect its steps only in a few instances ; but it is not 

 the less real and certain. The work of wear or abrasion has 

 never stopped since the first shower fell on the dry land, and the 

 first river began to run ; and it must ever continue while the 

 elements remain as now. Every exposed inch of the earth's sur- 

 face is wearing away more or less rapidly, and sending its minute 

 tribute of solid matter through the rivers to the sea. As this 

 waste of the dry land is swept out from the river-mouths into 

 the ocean, it becomes mingled with other sediments worn from 

 exposed coasts by the tides and the waves, or by sea-currents, 

 and all are borne together to the stiller waters beyond these 

 influences. There they gradually settle down to the bottom, the 

 coarser and heavier sediments falling nearest the land, the finer 

 and lighter particles being carried farther to sea. 



