Niagara Falls 



1809 not indeed so remarkably distinguish the limestone at the spot 



Mitchill where the cataract is; but, as the calcareous strata there possess 



the same general character with that in the adjoining districts, it 



was thought proper in drawing up this sketch, to mention the 



marks of the common saline and maritime origin. 



The silicious ingredients in the rocks hereabout were observed 

 by Dr. Mitchill to consist mostly of quartz and flint. The quartz 

 is sometimes mingled with the calcareous carbonate in such quan- 

 tity as to give sparks with steel; forming a sort of silicious lime- 

 stone. In other cases it exists in veins or streaks almost unmixed. 

 And lastly it bespangles the surface with elegant crystals, hard 

 enough to scratch glass. The flint of the falls is whitish; but 

 near the outlet of lake Erie it is blackish. In both places it is 

 distinctly bedded in the limestone; and their quantity is relatively 

 small, particularly at the former place. . . . 



Such, according to this gentleman's report, is the constitution 

 of the solid strata at Niagara, and in its vicinity. The upper- 

 most are horizontal and tabular; when a stratum is discontinued, 

 its termination is abrupt, forming a sudden descent. This descent, 

 at any one place, is proportional to the thickness of the stratum. 

 Several of these strata break off in this manner, about half way 

 between Chipeway and the grand cataract. And they continue 

 their interruptions to the evenness of the channel, the whole dis- 

 tance beyond. At each termination the river treads lower, and 

 skips and dances along to the next. It marches down this, and 

 proceeds to the succeeding one. Then it runs from stage to 

 stage, until after a gradual and majestic progress of a mile, gath- 

 ering force and velocity at every step, it leaps from the high and 

 final precipice. 



The mighty and immeasurable torrent dashes upon a ledge 

 of detached and enormous rocks, the fragments of the superior 

 strata that have been broken off, and precipitated in the course 

 of the ages. All the pieces which the vehement and unceasing 

 current can stir, are washed away. None remain but those that 

 are too heavy for removal. These form a rough and broken 



506 



