1874.] «^J- (Lesley. 



Practical Value op the Ores. 



The experience of sixty years has demonstrated the exact values of the 

 brown hematite iron ores of all the Lower Silurian Valleys of Pennsyl- 

 vania : on the Lehigh ; in the Great or Cumberland Valley ; in Kishico- 

 quilis Valley ; in Morrison's Cove, Canoe and Nittany Valleys. 



The general resemblance of ores from all the Banks is striking. The 

 local variations are still more striking. The key to those variations was 

 only got when the true geological theory of structure was studied out. 

 But it is still a perplexing question why red-short, cold-short and neutral 

 ores should lie so near each other. There is scarcely an ore bank in 

 Pennsylvania in which the chemist will not find some infusion of sulphur 

 and phosphorus. But some ores have teen so slightly charged with one 

 or other, or both of these elements, that they rank in the first class. 



Others are so heavily charged, that they are useless for Bessemer work ; 

 take a low rank as anthracite or coke iron ores ; and only make good pig- 

 metal when smelted in small quantities, with charcoal and a feeble cold- 

 blast. 



This is especially true of those of the lowest geological horison or 

 oldest in age, belonging to rocks of Pitsdam age, rocks which rise upon 

 the flanks of the South Mountain. Fortunately, these ores nowhere reach 

 the surface in Nittany Valley, being buried in the jaws of the Bellefonte 

 Fault. Even the Pennington horison is too high for these ores. 



The consequence is, that most of the ores of the district under notice 

 here yield a practically neutral oi-e and make the best possible iron in 

 cold blast charcoal furnaces, and good iron with the hot blast, and'min- 

 eral fuel. The appended analyses of Dr. Genth will make this fact evi- 

 dent. 



Phosphorus, however, is found in all known Silurian Brown Hematite 

 ores (with some rare exceptions) in quantity enough to prevent the man- 

 ufacture of steel. But in some cases mixture with other ores will rectify 

 the ore. In other respects the per centage of phosphorus is too small 

 to do hurt. Dr. Genth's analyses will give the figures in this case also. 



The reputation of Pennsylvania iron was greatly made at Pennsylvania 

 Furnace. Its quality could not be surpassed. Neither the older Swedish, 

 nor the best English, when English iron was still good, nor the more 

 recent magnetite pig-metal of Lake Champlain and Missouri, have ex- 

 celled it ; and it shared this reputation with furnaces smelting similar 

 ores. 



There are parts of the deposit in almost every Bank, which are sandy 

 and lean. These have been hitherto fastidiously rejec'^ed by the charcoal 

 coal blast furnaces of the district. Such ores are, however, in demand 

 for our anthracite and coke furnaces, and the ever-increasing market for 

 them will require the mining of the whole. I believe that carefully se- 

 lected ore from these banks will even furnish iron fit for Bessemer use. 



