366 FALLS, BREACHES, AND 



rials below. A thick and massy bed of this rock crosses 

 the river a little above the place where it descends. The 

 rock there divides itself into so many distinct masses, 

 that when the water is low or scanty, it runs through 

 four different chasms between the walls. When the river 

 is swelled with rains, all these fissures and interposing 

 mounds are covered up, and the distinction of current is 

 in some measure lost for about half the distance of their 

 irregular descent. The streams then assume a new mo- 

 dification, and arrive at the bottom by three principal 

 channels. The rocks which directs the courses of the 

 waters, and separate their currents, are almost as horizon- 

 tal as if they had been laid by a level. In several 

 places they are very abrupt, and terminate with the per- 

 pendicularity of a wall. Between them are the profound 

 openings through which the torrents force their way. 



These strata abound in shells and madrepores. In 

 the lowest they are least conspicuous. In the mid- 

 dle layers they are plainer; aad most distinguishable 

 above. The collection of fossil specimens made by Mr. 

 Miibert and Trecot, now in my possession, afford beauti- 

 ful illustrations of this distribution of organic relicks 

 through the rocks. 



Other features of this region are equally remarkable* 

 The surrounding scenery is a medley of detached 

 granite and gneiss, with sand, and other loose allu- 

 vial materials. These evidently were washed down 

 from Hadley, when the enclosed waters removed their 

 barrier, and bore every thing before them to this 

 lower country. 



At Fort Edward Falls, the bed of the Hudson is slate. 

 This shistic bottom is visible all the distance, wherever 



