T. G. B. LLOYD NOTES EROM THE STATE OE NEW YORK. 79 



Biver. The beds of Potsdam sandstone passed from a fine-grained 

 grit into a quartzite, the grains of which conld not be distinguished 

 without a lens. The upper surfaces of the beds were ripple-marked. 

 At a depth of about 6 or 8 feet below the surface the peculiarly- 

 shaped blocks, or columns, were discovered. I observed a few lying 

 about, which had been extracted by the quarrymen ; one of the 

 largest was 2 feet high, 2 feet in diameter at upper surface, and 1| 

 foot on the lower surface. They were broken off at the lines 

 separating the beds of sandstone. They corresponded exactly in 

 texture and colour with the surrounding rock. On the edges of the 

 blocks were thin layers of oxide of iron, easily detached by a blow. 

 The surrounding rock was here and there streaked with the same 

 substance. A short distance away from the quarry was a large 

 mass of rock of a similar shape, and about 5 feet in diameter, which 

 had apparently been dislodged from a hole close by it. There were 

 no markings on the surface of the blocks. Prof. James Hall, of Al- 

 bany, informed me that the true nature of the blocks was doubtful. 



