of the Town of New-Haven. 95 



an angle if more than Q^ or 10° with the horizon, and 

 rest upon a stratum of sand stone, having the same in- 

 clination in degree and in direction, which is south- 

 west. 



From the West Rock, we bend our course westward 

 and southward, along the brow of the hills, which now 

 assume only a very moderate elevation. Frequent masses 

 of granite, whin stone, quartz and sand stone accompa- 

 ny us along through Westfield, till we arrive within a 

 quarter of a mile of the Derby turnpike, when a new 

 species of stone presents itself, and very soon becomes 

 the predominate stone of the country. Its color is blu- 

 ish, inclining to white, its fracture hackly, its hardness 

 is such that it may be scratched even by the nail. Its 

 structure is schistose, the lamina are often variously 

 contorted, and frequently striated, with laminae of quartz, 

 and sometimes of mica, so that in many places it may be 

 called micaceous schistus, and from its soapy feel it may 

 •generally be denominated magnesian schistus. 



There are considerable varieties in its appearance ; 

 sometimes it inclines towards argillaceous schistus, or 

 slate, but is distinguished from it, by its soapy feel, and, 

 other times it approaches the character of serpentine. 

 Here and there in this quarter, may be seen detached 

 masses of porphyry, which seems capable of receiving 

 a handsome polish, but no bed of it was observed, al- 

 though it is more than probable it exists in the adjacent 

 hills in considerable quantity. 



Nothing occurs to detain us in passing over the hills 

 which lie between the Derby turnpike, and those heights 

 which overlook West-Haven, about midway between 

 the Sratford road, and the Sound. Insulated blocks of 

 granite, whin stone, porphyry and quartz are scattered 

 every where along, but the magnesian schistus is pre- 

 dominant, and from the heights just now mentioned, to 

 where they terminate in the flat ground, adjacent to the 

 shore, we find nothing but immense strata of this 7nag- 

 nesian schistus, rising every where to view, and discov- 

 ering, whenever the road, a water channel, or a side- 

 hill gives a vicAv of the strata, an unvarying inclination 



