L. MECHANICS AND ENGINEERING. 461 



the furnace until it is cooled, emits such large quantities of 

 combustible gas as to be covered with a continuous layer 

 of flame. Even after cooling this difference is to be traced 

 in the fact that the manganiferous iron retains a much 

 larger proportion of gaseous constituents than the other, hy- 

 drogen of course predominating. Thus a quantity of cast 

 iron yielded 16.7 parts of mixed gases, while the same weight 

 of spiegeleisen gave up 29.5 parts. Carbonized manganese 

 was found by direct experiment to absorb a much greater 

 amount of hydrogen than iron containing the same propor- 

 tion of carbon. 6 B, April 5, 909. 



STEEL DIRECT FROM THE ORE. 



The system JPonsard, for producing steel direct from iron 

 ore, has attracted much attention. La MetaUurgie gives the 

 following account of an experiment made on this system: 

 For several years metallurgists have essayed to treat iron 

 ores in a reverberatory furnace instead of the blast-furnace, 

 which, besides being very costly, can only, as yet, be worked 

 with coke or charcoal, of which the cost has largely increased 

 of late years. All the attempts made in Europe and Amer- 

 ica have heretofore been unsatisfactory ; but the problem 

 has at last been solved. On the 27th of September, at the 

 forge of the Verrieres, at Vienne, France, the first produc- 

 tion of pig-iron by the direct treatment of the ore in the gas 

 reverberatory furnace, system Ponsard, took place under the 

 superintendence of the inventor, with the assistance of M. 

 S. Perisse, director of the General Metallurgical Society of 

 Paris. The apparatus consists principally of a gazogene 

 which transforms the fuel in a series of larsre chambers, and 

 of a brick appendage, called the recuperator of heat, which 

 receives the flames from the furnace, and restores the caloric 

 in the form of hot air. The compartments of the chamber 

 serve successively for the reduction of the ore, for the re- 

 actions which are effected, and, finally, for the fusion of the 

 whole charge in such a manner that the separation of the 

 component parts is effected by the difference of density. 

 These various phases of the operation require very different 

 temperatures, and the production of these is the special ob- 

 ject of the apparatus. On the side of the furnace doors the 

 temperature is only that of red heat, while beyond the heat 



