OF MARYLAND. 45 



acting upon its surface, that have removed perhaps more than 

 two-thirds of the vvliole mass, as it existed at its first deposi- 

 tion, without affecting the dip or inclination of the strata. The 

 accompanying rocks are those usually found in coal-measures; 

 namely, sandstone, limestone, slates and shales, containing but 

 few organic remains. The Focus Alleghaniensis and some 

 Calamitcs are seen in the sandstones, the nodules of argilla- 

 ceous iron-ores envelope impressions of leaves and stems of 

 some undetermined plants, and the limestone contains Tere- 

 hratulca. 



No coal has been found on the east side of Dan's mountain, 

 the millstone grit that occurs at its summit, being replaced at 

 its base by limestone and red sandstone. In the valley of 

 Braddock's run, also, the prevailing rocks are the red sand- 

 stone \vith compact limestone of various colours; they contain 

 no organic remains, and their strata are nearly vertical. The 

 gap in Wills's mountain, which presents a great natural sec- 

 tion of the ridge from ten to twelve hundred feet wide, extend- 

 ing to the base of the mountain and forming an excavation of 

 not less than eight hundred feet in depth, exhibits the red 

 sandstone as forming the base of the mountain, with superim- 

 posed strata of a fine grained white sandstone. On the north- 

 western side of the gap, the strata of white sandstone are nearly 

 vertical, they curve over the sunmiit of the mountain, and on 

 its south-eastern side descend at an angle of about 30° to its 

 foot, where they are covered by a blue limestone. 



In the vicinity of Cumberland the rocks are limestone and 

 slates. Some of the limestones are slightly bituminous, and 

 their mass is traversed by large veins of quartz, that having 

 offered more resistance to the disintegrating effects of water 

 and atmospheric agents, occasionally protrude much beyond 

 the rocky strata with which they are associated. They then 

 occasion remarkable appearances in the rocky masses of the 

 moutitain, that never fail to attract the attention of the i»no- 

 rant, who, unable to account for them, are yet very ready in 

 assigning to them an object. An occurrence of this kind, on 

 the north-west slope of Wills's mountain, has in this way 

 received the namxC of tiie Devil's sliding place. Between 

 Cumberland and Sideling hill — being a succession of ridges 

 and spurs from more lofty ones — the rocky strata consist of 



