462 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



is so great that the eye is unable to support the intensity of 

 the glow. This extraordinary heat is estimated at 2000 

 Centigrade. 



The success of the experiment is reported to have sur- 

 passed all expectations, and the result obtained is considered 

 to demonstrate the possibility of producing steel direct from 

 the ore, without any of the transformations necessary under 

 existing systems. Of course, this is a novelty in the history 

 of metallurgical industry ; and it is almost unnecessary to 

 add that, should the system in daily practice justify the re- 

 port, it will prove a revolution indeed. 3 A, Oct. 24, 1874. 



REVOLVING FURNACE FOR PUDDLING IRON. 



A revolving furnace for puddling iron, the invention of 

 Mr. Crampton, has lately been presented to the notice of the 

 Iron and Steel Institute of Great Britain. Small coal or 

 slack is utilized as fuel, and is introduced with a current'of 

 air in such a way as to insure perfect combustion, and the 

 consequent absence of smoke. An intense though regular 

 temperature is obtained. A great economy of fuel is claim- 

 ed for this apparatus, as well as great rapidity of action ; 

 since, with a furnace twelve feet in length and six in diam- 

 eter, the inventor has puddled pig-iron in an hour and a 

 quarter from the time it was cold. 16 A, Oct., 1874, 539. 



MAGNETIC ORE SEPARATOR. 



A magnetic ore separator has lately been invented by Mr. 

 King, in England, for the purpose of separating iron ore from 

 other minerals when associated with them. It is at present 

 employed at the Ballycorkish Mines, on the Isle of Man, 

 where the ore consists of a mixture, of galena, blende, and 

 spathose iron ore. The galena can easily be set free, in con- 

 sequence of its greater specific gravity; but the blende and 

 the spathic ore can not be separated by any ordinary means. 

 A perfectly satisfactory result is obtained, however, by means 

 of the magnetic ore separator. The ore, after being crushed, 

 is roasted at a dull red heat in revolving retorts, when the 

 carbonate of iron is decomposed, and a magnetic oxide pro- 

 duced. The ore is then transferred to the hopper of the 

 magnetic apparatus, which consists of a large drum wheel 

 about eighteen inches in diameter and ten in breadth, fur- 



