On the Coal Formations in the State of Neiv York. 327 



stratum which embraces the Tioga coal ? or wliether he only means 

 that it belongs to the same (third grey wacke) formation ? I had been 

 induced to believe that our slate is a different stratum, from consid- 

 ering that there is a general dip in all our rocky strata to the south.* 

 It is also to be observed, that our slate is overlaid by harder rocks, 

 which contain a much greater portion of siliceous matter; and are 

 so little affected by exposure to the weather, as to have been quarri- 

 ed for building stone, in particular localities. Much of this kind, on 

 account of its smoothness, durability, and regular form, has been ta- 

 ken down the Seneca lake to Geneva j and some beautiful pieces 

 wexe used in constructing the old stone locks on the Seneca outlet. 

 The hill immediately south of Ithaca village, which almost closes the 

 valley of the Cayuga, also contains a much harder rock, and appears 

 to cover up the last traces of our soft slate in a southerly direction. 



These circumstances render it not improbable that our slate con- 

 tinued with the same dip, underlays the Tioga coal, which is proba- 

 bly seven hundred feet above the Seneca lake, at a depth of many 

 hundred feet ; and that the slate traced by Prof. E. belongs to differ- 

 ent strata, separated by harder varieties of greywacke. 



How far our rocky strata may be traced to the south, I have yet 

 to learn. In the valley of Towanda creek, twenty miles below Tioga 

 Point, near an extensive deposit of bituminous coal, a red rock oc- 

 curs ; and salt has been manufactured in that vicinity. Red sand- 

 stone and salt springs also occur in the elevated region to the south- 

 westward. I have procured salt from those waters. 



Is that saliferous rock in the same stratum as the saliferous rock of 

 this district ? If it is, our incumbent strata (limestone, slate and 

 greywacke) must terminate north of the Towanda ; and the salifer- 

 ous stratum, south of our lakes, must very considerably ascend, at 

 least on its upper surface. 



When we discovered the carburetted hydrogen in the Erie canal, 

 six miles east of Lockport, I was much surprised, as all the fountains 

 of this kind which I had previously seen, were in the pyritiferous 

 slate. I accord with Prof. E. however, in his views on this subject. 



^ The idea appears not to have occuiied to Prof. E. at the uioiaent oi writing, for 

 he says, " The layers of this [carboniferous'] rock are always horizontal or nearly 



