CLINTON COUNTV. 309 



like paving stones, and derived from the potsdam, are mixed. In otlicr places the roek is very 

 much exposed, as upon Rand's hill, where it is laid bare, and without sufficient soil to support 

 any but the smallest shrubs, except where tlicy take root in the cracks or natural joints of the 

 rock. This rock, too, furnishes two or three varieties which I have not recognised in other 

 places. 



1. The ordinary fine-grained, grey or brown sandstone, crystallized on a large scale, in coarse rliombic prisms, similar to 



the rock at Keeseville. 



2. Deep red sandstone, stained witli oxide of iron ; it occupies the lowest position. About ten miles east of Plattstiurgh 



on the Military road, and in West-Chazy two miles southwest of Lawrence corners, tliis variety is common, forming 

 the lowest layers of the rock. 



:!. White granular and friable sandstone, in the town of Moocrs. Sometimes it has the whiteness of loaf-sugar, and 

 disintegrates into sand ; it is a line material for flint glass. 



4. Dark iron-brown or black sandstone, traversed by scams of quartz; it resembles, as a whole, some of the varieties of 

 greywackc. It forms one of the masses at Chazy, It occupies a superior position in the rock, and in conjunction with 

 the succeeding, is not less than one hundred feet thick.* 



a. A brecciated mass, associated with the preceding. It contains fragments of luncstone, resembling the ealciferous sand- 

 rock. 



6. Conglomerate, which usually occupies the lowest place : but on the northwest border of Clinton, the whole mass par- 

 takes of this character. 



This rock extends two miles west of the Redford glass-works. At this place it is probably 

 separated from the main mass by a range of granite, which extends through Saranac, and 

 from thence northwards several miles in the rear of Rand's hill. Although this rock is of the 

 common grey variety similar to that at Port Kent and Keeseville, still it burns white, and is 

 employed almost exclusively in the manufacture of the Redford crown glass, which has be- 

 come known to community for its beauty and strength. Probably most of this rock is suitable 

 for this use. It is the common rock which is employed, though in Mooers a fine white variety 

 is abundant. It is essential, however, that it become white in burning. 



Of the varieties described above, Nos. 4 and 5 appear to be entirely local. I have not seen 

 them except in Clinton. The others are common. 



I had occasion, when describing this rock in Essex county, to speak of the remarkable 

 gorge at Keeseville, and through which the Ausable flows. A still larger fracture exists in this 

 rock near the Provincial line ; or it is said that the boundary passes through it, the town of 

 Mooers being south, and Canada north. However this may be, the place itself is very widely 

 known under the name of Flat-rock. Covey hill is sometimes spoken of as the place where 

 this fissure occurs. It is sixteen miles west from Champlain. 



The fissure, or gulf, as it is usually called, is three hundred feet deep, and about sixteen 

 rods wide. Its walls of sandstone or conglomerate are perpendicular at the deepest part. The 

 small lake at the bottom is said to be one hundred and fifty feet deep. The direction of this 

 fracture is north seventy degrees west, and the rock dips at a small angle from each side of 



* Boulders of this mass are scattered over the fields in this town. There is one, half a mile southwest of the village of Chazy, 

 twenty.five feet lon^, twenty wide and eight thick. 



