258 



PENNSYLVANIA. 



The Tioga is a feeder of the eastern branch, and rises north of the mountains, near the 

 boundary of New York ; it is navigable for boats 50 miles. The MUghany rises west of the 

 mountains in the northern part of Pennsylvania, and flows northerly into New York, where it 

 curves to the southwest, and reenters Pennsylvania ; it then flows south, till, afler a course of 

 400 miles, it joins the Monongahela below Pittsburg. This last river has its source among 

 the Laurel Mountains, in Virginia, and running north, enters Pennsylvania, and joins the Alle- 

 ghany at Pittsburg ; it is 300 miles in length. Both these rivers have a boat navigation for a 

 great part of their course, and their united waters form the great stream of the Ohio, which, 

 after a short course, passes out of this State. The Youghiogeny is a tributary of the Monon- 

 gahela, and rises east of the Laurel Mountains, through which it passes, and runs into the Mo- 

 nongahela, L5 miles above Pittsburg. The Ohiopyle Falls are upon this river. 



5. Harbors. About 40 miles of the northwestern border of the State lie upon Lake Erie ; 

 this extent of coast contains the harbor of Presqu'' Isle, or Erie, which affords a good haven for 

 small vessels. 



6. Climate. Under this head, Pennsylvania may be regarded as comprising three separate 

 divisions, namely, the eastern slope of the mountains, the mountainous region, and the western 

 slope. In the country east of the mountains, the climate does not differ greatly from that part 

 of New Jersey in the same parallel. Its greater distance from the sea, and somewhat higher 

 level, render the cold of winter in a slight degree more sensible, but the climate may be charac- 

 terized in general terms as mild and temperate. The mountainous country lies exposed to the chill- 

 ing northwest winds, and the winter in this part is severe, with deep snows. West of the moun- 

 tains, the climate becomes milder ; here the easterly winds of the Atlantic coast are unknown, 

 and the country is not exposed to the sudden changes which they occasion. The heat of sum- 

 mer is not so great as upon the coast, and the autumn is long, serene, and temperate. 



7. Soil. To the east of the mountains, the soil is excellent ; in this part, the land is level, 

 and enriched from the washing of the hills and uplands. In the interior, the soil is rocky and 

 barren, with fertile spots in the valleys, and along the borders of the streams. Some of these 

 valleys contain land as rich as any in the State, the soil being generally a black mould two or 

 three feet deep ; but among the mountains, it is not well adapted to cultivation. West of the 

 mountains, the country improves, and around the head streams of the Ohio, is generally fertile. 



8. Geology and Minerals. Pennsylvania is characterized by the inexhaustible abundance, 

 rather than by the variety, of its useful minerals ; iron-ore of several species, lime, marl, sand- 

 stone, clays, and slates, serviceable for agriculture, architecture, and other economical purposes, 

 salt, and coal, occur in profusion ; but the pretended deposits of silver and tin, lead, zinc, and 

 copper, assigned to various localities, have no existence. By far the greater portion of the 

 rocks belong to the secondary formations of the lower series, only the southeastern section fur- 

 nishing some members of the transition and primary groups. The rocks of the Blue Ridge, 

 comprising various slates, sandstones, and conglomerates, are referred to the former ; east of 

 this extends a newer group of red shales and sandstones, and variegated conglomerates, the pro- 

 longation of the belt ranging across New .lersey. Still another portion of this region is occu- 

 pied by primary rocks of the stratified class, consisting chiefly of micaceous gneiss, mica, tal- 

 cose, and chlorite slates, limestones, &c. Valuable deposits of magnetic iron-ore here, as else- 

 where, characterize the primary strata, and traces of zinc (blende) and copper occur in the red 

 sandstone formation ; but the ores are not in sufficient quantity to be workable. The city of 

 Philadelphia is indebted to the limestone beds of this tract for the beautiful marbles which adorn 

 her streets. The rock formation of the great valley west of the Blue Ridge, consists of alter- 

 nating belts of limestone and slate, occupying a low place in the geological series, and perhaps 

 belonging to the transition group. The limestone is often argillaceous and slaty, generally blue, 

 sometnnes fossiliferous, and occasionally assuming the aspect of a marble, either pure white or 

 of a gently variegated hue, witli a fine, even fracture, susceptible of a beautiful polish. Some 

 bands yield an excellent hydraulic cement, the usual place of which is near the contact with the 

 slates ; hematitic iron oi 3, which is easily reduced, and yields a large proportion of metal of su- 

 perior quality, is also plentifully associated with these limestones. Some of the slate strata afford 

 quarries of good roofing and writing slates. 



The vast tract west of the Blue Mountains is divided by the Alleghany ridge into two strongly 

 markea regions, of widely different aspect and geological structure ; that on the east, compris- 

 ing the various chains of the Kittatinny group, consists of numerous alternating strata of lime- 

 stones, slates, shales, and sandstones, which have been broken up and thrown into great disorder, 



