clxxiv GENERAL SUMMARY OF SCIENTIFIC AND 



than hand-puddling a fact demonstrated by actual expe- 

 rience here and abroad; and the quality of the product is 

 such as to command a higher jnlce than that produced by 

 hand from the same pig. 



On the whole, it would appear that every where the me- 

 chanical system is gaining advocates, and it is fair to pre- 

 sume that most of the difficulties that now surround the 

 problem will be obviated with a few years more of practice. 

 The plan lately invented by Mr. Crampton appears, incident- 

 ally remarked, to be a decided improvement, and is now 

 being largely introduced in England. 



Mr. Crampton employs coal-dust fuel in his rotary furnace, 

 and has introduced other novel features, chief among which 

 is his method of constructing the water-casing, the chamber 

 beinsr lined with oxide of iron. The o-eneral results of Mr. 

 Crampton's invention clearly demonstrate that, in the first 

 place, slack or small coal can be utilized, and that coal-dust 

 and air can be fed automatically a matter that has sorely 

 tried many who have endeavored to eifect that object. 



We may be able in our next Annual Record to announce 

 material progress in this field. 



The most interesting item connected with the metallurgy 

 of Iron, originating on this side of the Atlantic, is the bring- 

 ing out, at the spring meeting of the American Institute of 

 Mining Engineers, of a new process for iron and steel making, 

 by Thomas S. Blair, of Pittsburgh. The process in question 

 produces malleable iron directly from the ore. Its essential 

 feature consists in the production of an " iron sponge," which, 

 according to the quality of product required, may be sub- 

 sequently melted down in a bath of cast iron, the propor- 

 tions being so chosen as to produce ingots of any desired 

 degree of carburization. In the production of the metal 

 from the ore, the temperature to which it is subjected is not 

 raised so high as to melt the iron, and consequently the 

 deoxidized iron retains the form of the ore introduced, but 

 possesses a spongy texture, whence the name applied to it. 

 This sponge presents so large a surface to the air, that if 

 permitted to come in contact with it while hot, it readily 

 oxidizes and returns to its original condition of sesquioxide. 

 It is necessary therefore that it should cool before coining 

 into contact with the air. The construction of a furnace in 



