1874.] J-'J^ [Lesley. 



charcoal furnace use, in the presence of the magnificent deposits of brown 

 hematite in the Lower Silurian Limestones (No. II). 



But from the neighborhood of Tyrone City Gap southward, past 

 Frankstown, Holidaysburg and Bedford, they have paid well for mining, 

 and continiie to furnish an apparently inexhaustible fund of 30 per cent, 

 to 40 per cent, ore to the large coke-furnaces of Blair and Cambria 

 Counties. 



By comparing my larger topographical Map with Mr. Lowrie's Land 

 Map it will be seen that the out- crops of Fossil Ore on Lyon, Shorb & 

 Co.'s lands range in an unbroken line from the AbnerWebb tract to the 

 Shippen tract, a distance of ten and a half (10^) miles, and always in an 

 attitude nearly or quite vertical ; failing off at the south end to 60° W. 

 N.W. 



The geological order of the beds at Frankstown, where they are exten- 

 sively mined, is by careful measurement as follows : 



Red Shale of No. V. (Clinton Group.) 

 e. Soft fossil ore, small single bed, 3 to 8 inches. 



Red Shale, 100 feet. 

 d. Soft fossil ore-bed. \ 



Yellow ochre, 10 feet. [ In all 25 to 40 inches, 



c. Soft fossil double ore-bed. J 



Red shales and some thin sand stones, 400 feet. 



Chocolate slates, 20 feet. 

 6. Frankstown main soft ore-bed, 14 to 16 inches. 



Grey and dove colored slates, 17 feet. 



Red sand stones and shales, 155 feet. 

 a. Hard fossil ore-bed, about 10 feet. 



Red and grey sand stones of IV, to the crest of the Mountain, say 700 

 feet. 



a. HARD FOSSIL ORE BED. 



This is a layer of sand charged with peroxide of iron and full of minute 

 fossil shells and encrinal discs the calcareous parts of which are dissolved 

 away. It forms a bed of ore yielding by analysis about 30 per cent, of 

 iron ; and in the furnace %\ to ^\ tons of it make a ton of metal, always 

 cold-short, and therefore chiefly valuable when mixed in proper propor- 

 tions with other ores. 



Prof. Persifor Frazer's analysis of specimens taken from the middle 

 bench in Dysart's Mine recently opened (see smaller Map), made for me 

 in his laboratory in the University of Pennsylvania, is as follows : 



Specific gravity : 3.26. 



Sesquioxide of iron 38.48 ) Metallic iron 



Protoxide of iron 4.37 ) 30.34 



Silica 37.99 



Alumina 9.56 



Lime 1.08 



