clxxvi GENERAL SUMMARY OF SCIENTIFIC AND 



that has baffled the best metallurgical skill. The system is 

 termed that of Ponsard (from the inventor), and resides in 

 the direct treatment of the ores in a reverberatory gas-fur- 

 nace of peculiar construction. Its essential features are a 

 jxazo2;ene, which transforms the combustible into the gaseous 

 state ; a large chamber of many compartments, in which the 

 operations are conducted ; and an apparatus in brick called 

 the "Recuperator," which absorbs the waste heat of the fur- 

 nace, and gives it back in the form of hot air. The compart- 

 ments of the working chamber serve successively for the re- 

 duction of the ore, for the reactions that are to be effected, 

 and finally for the fusion of all the materials, so that a sepa- 

 ration by virtue of difference of densities is made possible. 

 These several operations require for their performance very 

 different temperatures, and the Ponsard furnace, by its pe- 

 culiar construction, meets the requirements of the case. 



The first experimental run of steel upon the process here 

 described was made on the 27th of September last, at the 

 iron works of Les Verrieres (Vienne), and is declared to have 

 been quite successful ; so much so as to warrant the an- 

 nouncement that steel may be produced direct from the ore, 

 without passing through the roundabout and complex proc- 

 esses hitherto employed. 



The fluorine process of purifying iron, invented by Mr. James 

 Henderson, was introduced into this country during the past 

 year at the works of the New Jersey Steel and Iron Com- 

 pany, Trenton ; and the firm of Tuckerman, Mulligan, & Co., 

 of the Ulster Iron Works, Saugerties, New York, are about to 

 introduce it into their works. We have no space to enter into 

 details, that are probably already well known to most of our 

 technical readers through the journals, but may add that in 

 the preliminary trials of the process at Trenton the most in- 

 ferior cinder pig-iron that could be procured was used to test 

 its value, and the result was a bar-iron of very superior quality. 

 Again, ordinary anthracite pig-iron was made into the finest 

 quality of wrought iron, which was equal to that from the 

 best brands of Swedish iron. These trials remove any doubts 

 that may have existed hitherto in the minds of the practi- 

 cal men who witnessed them, of the economical application 

 of the process for the production of the higher grades of 

 wrought iron. 



