24 PHYSICAL GEOGRAPHY 



AKTICLE II. 



Outlines of the Physical Geography of Maryland, embracing 

 its prominent Geological features. By J. T. Ducatel, 



State Geologist, <fcc. 



[Read before the Academy, February 16 and March 3, 1837.] 



The political boundaries of the state of Maryland, as it is 

 usually represented upon the maps of the Union, are to the N. 

 a straight light running from 1° 1' E. Ion. to 2° 3' W. of Wash- 

 ington, which separates it from the state of Pennsylvania; to 

 the E. a line nearly at a right angle with the preceding, from 

 the 39° 43' N. lat. to the 38° 27' divides it from Delaware, the 

 remaining portion to the 38" being bounded by the ocean ; at 

 its south-west extremity it is separated from Virginia, by an 

 east and west line drawn through VVatkins' point, whilst its 

 principal southern boundary is determined by the course of the 

 Potomac — assuming the northern branch of the river to be its 

 main branch ; and its western limit finally, is formed by a 

 meridian passing through the first fountain of the latter river to 

 the Pennsylvania line; the territory beyond this last boundary 

 being also occupied by the state of Virginia. The space 

 included between these limits presents a surface of 10,000 

 square miles, of which about 1,2U0 are covered by the waters 

 of the Chesapeake bay, forming an extent of coast, including 

 the shores of the great tributaries to this inland sea from tide 

 water, of not less than 1,500 miles open to deep water naviga- 

 tion. 



The characteristic features of the Chesapeake bay are 

 those of a large arm of the sea, which, measured from its inlet 

 between the capes of Virginia to the mouth of the Susque- 

 hanna, is 220 miles in length, with an average breadth of 10 

 miles, throwing out numberless branches in the form of deep 

 creeks that penetrate far inland, and serving as the estuary 

 to numerous large rivers. Among these, in Maryland, the 

 principal on the Eastern Shore, are the Pocomoke, Nanticoke, 

 Choptank, Chester and Elk, and on the Western Shore, the 

 Susquehanna, Patapsco, Patuxent and Potomac. The limit 

 to which the oceanic tide reaches in them varies. On the 



