A GEOLOGICAL HISTORY. 41 



were first brought up, were when dried, a dust of 

 gray Sandstone. After passing through this Sand- 

 stone, and just before they stopped operating, they 

 came to the harder rock, the borings of which 

 contained grains of Mica, Quartz and Feldspar. 

 The two borings had at first sight a similar appear- 

 ance, but the upper had no Mica in its compo- 

 sition. From the presence of Feldspar and Mica 

 in the lower borings and from the greater hard- 

 ness of the material, it is to be inferred that the 

 Granite was reached, for whenever Mica accom- 

 panies the red Sandstone of this region, it has a 

 large portion of per-oxide of iron, (which colours 

 it red,) some clay, and is soft and easy to work. 

 The hardness of the bottom rock, and the difficulty 

 with which it was pierced, caused the stopping of 

 the operation and no fresh water was obtained at 

 this place. 



At the side of the Weehawken hill road, soon 

 after you pass the " William Tell House," the 

 Granite shows itself, underlying the red Sandstone, 

 which is in this place very thin, and altered by 

 the trap that overlies it. 



2nd Serpentine. — (See plate 2, fig. 2.) This 

 rock is a different kind of Serpentine* from any 



* In 1824, I undertook to make Epsom Salts of this rock, but was foiled 



6 



