14 Report on the projected Survey of the State of Maryland. 



mine hanh, situated on the east side of the Washington Turnpike, 

 near the twenty-first mile stone., and about half a mile from the 

 road. The ore was formerly extracted from this bank in large quan- 

 tities, as is evident from the excavation — but the mine is now totally 

 abandoned and serves as a mere lick, to which the cattle of the 

 neighboring country are attracted by a singular efflorescence within 

 o[ sulphate of magnesia. 



At the head of deep run, which empties into the Patapsco, seven 

 miles from Baltimore, ore of a good quality is raised for the use of 

 the Patapsco furnace. The furnace at Curtis's creek is fed whh ore 

 of the same nature, principally from its own neighborhood ; and in 

 the immediate vicinity of Baltimore, where it occurs in abundance, 

 advantage is taken of the facilities of the rail road to convey it to the 

 water side, whence it is exported to New Jersey, and there exchang- 

 ed for bog-ore. 



On the falls of the little gunpowder, at Joppa, and near Abingdon, 

 in Harford county, there are extensive deposites principally of that 

 variety called in the arts brown ore, which is of the best quality. 

 Along Bush river in the same county, the best quality of hone ore is 

 raised. This latter variety is a mixture of carbonate and oxide 

 of iron, and is said to produce the best foundry iron. Hone -ore, 

 generally yields a more valuable metal for castings ; while the brown 

 ores furnish the best forge-pigs. The furnace of Bush creek is in 

 •part fed with these ores. Others, with which it is supplied from 

 the upper part of Harford county, will be described hereafter, but 

 lit may be proper to mention here, that associated with what is 

 obtained from Bush river, there is a mineral, apparently a ferruginous 

 Jasper, which by some iron masters has been termed flint ore. This 

 is not an ore of iron ; but, on the contrary, is a pernicious article when 

 suffered to go into the furnace. 



Such are the principle known localities of iron ore in this section 

 of the state of Maryland. There are doubtless others of equal ex- 

 tent and value ; and it is known that ores of inferior quality, but an- 

 swering admirably when mixed with the richer refractory ores, also 

 abound. It is not deemed necessary to specify these at present. 



Besides all of these, however, which have just been briefly de- 

 scribed as belonging more immediately to the tertiary formation ; 

 there is found in its upper limits among the erratic material with 

 which it is associated and occurring very often in very large masses, 

 another variety described mineralogically as hematitic brown oxide of 



