MARYLAND. 



273 



ginia, a distance of about 30 miles, with an average breadtli of 6, and an area of nearly 200 square 

 miles. The coal lies in a trough between Dan's and Savage Mountains, and occurs in nume- 

 rous beds, alternating in the lowest portion of the deposit with slates, shales, bands of iron ore, 

 and slate clay, and in the upper parts with strata of shale, sandstone, and limestone. Beyond 

 the Back Bone is the Youghiogany or Yohagany coal-field, where there are coal-seams 20 feet 

 thick. The iron ore beds in some instances alternate with the coal strata, and the ores belong to 

 the argillaceous carbonate, and red and brown hematites. 



POLITICAL GEOGRAPHY 



1. Divisions. Maryland has 20 counties,* and in common language is considered as com- 

 prising 2 great divisions, separated by the Chesapeake, viz. the Eastern Shore, and the West- 

 ern Shore. 



Population at different periods. 



1790 

 1800 

 1810 

 1820 

 1830 

 1840 



Whites. 



208,649 

 21C,326 

 235,117 

 260,222 

 291,108 



Slaves. 



103.036 

 105,635 

 111,502 

 107,398 

 102,994 



Free Colored. 



8,043 

 19,587 

 33,927 

 39,730 

 52,938 



Total Colored. 



111,079 

 125,222 

 145,429 

 147,128 

 155,932 



Total Pop. 



319,728 

 341,548 

 380,546 

 407,350 

 447,040 



2. Canals. The Port Deposit Canal is 10 miles in length, passing along the Susquehanna. 

 The Chesapeake and Ohio Canal is designed to unite the Potomac at Washington, with the 

 Ohio at Pittsburg. It will be 340 miles long, and 60 feet wide. Its course is along the north- 

 ern bank of the Potomac, and it is nearly completed to Cumberland, 185 miles. 



3. Railroads. The Baltimore and Ohio Railroad is designed to extend from Baltimore to 

 Wheeling, 360 miles. A mile and a half from the city is the Carrollton Viaduct, 312 feet in 



length, and 40 feet high, built 

 of granite, with an arch of 80 

 feet over a stream running 

 into the Patapsco. Two oth- 

 er viaducts are in the same 

 neighborhood, one of which is 

 375 feet long, and crosses the 

 Patapsco on 4 arches. When 

 this great wbrk is finished, the 

 whole distance from Baltimore 

 to Wheeling will be traveled 

 in 20 hours. The Carrollton 

 viaduct is shown in the annexed 

 cut. A branch of this road 

 extends to Washington, 32 

 mdes, and a viaduct across the Potomac at Harper's Ferry, connects the main line with the 

 Winchester Railroad. The work is now nearly completed as far as Williamsport. The Philadel- 

 phia and Baltimore Railroad, 93 miles in length, extends within this State, from Baltimore to 

 Havre de Grace, where the Susquehanna is crossed by a steam ferry-boat, and thence to Dela- 

 ware towards Wilmington, a distance of 53 miles. The Baltimore and Susquehanna Rail- 

 road extends from Baltimore up the Great Falls of Gunpowder, and down the Codorus to York, 

 in Pennsylvania, 60 miles, whence it is continued to Columbia by the York and Wrightsvillc 

 llailroad, 13 miles. The Annapolis and Elk Ridge Railroad, 20 miles, is in progress. 



* Eastrrp. Shore. 

 Caroline 

 Cecil 



Dorchester 

 Kent 



Queen Anne 



Somerset 



Talbot 



Worcester 



Western Shore. 

 Alleghany 

 Anne Arundel 



Baltimore 



Calvert 



Carrol 



Charles 



Frederick 



Hartford 



Montgomery 

 Prince George s 

 St. Mary's 

 Washington. 



