MECHANICS AND USEFUL ARTS. 55 



of iron castings, which, although containing manganese, can- 

 not be converted by the Bessemer process, on account of the 

 quantity of carbon, sulphur, or phosphorus which they contain. 

 It is, in fact, now proved that the Bessemer process, far from 

 eliminating the sulphur and phosphorus, tends rather to augment 

 the proportion of these metalloids. 



" The cast irons known as cJiaudes, and which contain silicium 

 and magnesium, owe a part of their superiority to the calorific 

 power of the silicium (7,800), the produce of the oxidation of 

 which, silica, requires but little heat to disengage it, so that the 

 liquefaction becomes more complete. On the other hand, carbon, 

 under the same conditions, gives rise to the disengagement of 

 masses of sparks produced by the gases, carbonic acid and car- 

 bonic oxide, which traverse the mass ; these take from the molten, 

 matter a considerable quantity of caloric, and are thus unfavorable 

 to liquefaction. 



"In our process this latter inconvenience is partly dispelled ; 

 for the gases produced by the combustion of the carbon, sulphur, 

 and phosphorus, combining with the soda or potash, are mechani- 

 cally carried through the mass of metal by the oxidation of the 

 sodium of potassium. The direct action of the sodium or potas- 

 sium, in the form of vapor, on the melted iron, may be replaced 

 by adding to the mixture of ore, fuel, and flux, either chloride of 

 sodium, carbonate of soda, a corresponding salt of potash, or a 

 mixture of these. 



" Acting thus on any given ore, and using coke or coal as fuel, 

 a result analogous to that obtained with charcoal under the ordi- 

 nary system is obtained. We must add, however, that in the 

 former case the current of hot or cold air should be longer main- 

 tained than when charcoal is used ; this prolonged application of 

 hot or cold air in the blast furnace may present inconvenience, 

 which may be avoided by directing the alloys of cast iron with 

 sodium or potassium into a converter, in which they may undergo 

 the final action of the current of air ; with this process the work- 

 ing of the blast furnace is the same as in ordinary cases. 



"We arrive practically at an assimilation of the coke or coal 

 with alkaline salts corresponding to those furnished by wood 

 charcoal, either by watering the fuel with the alkaline solutions 

 above mentioned, and then allowing it to dry in sheds ; or, lastly, 

 by pouring a concentrated solution of the various salts on the fuel 

 or the ore at the moment of charging the furnace. We intend to con- 

 tinue our experiments on the alloys and combinations of sodium 

 and potassium with most of the other metals." Scientific Ameri- 

 can. 



IMPROVEMENT IN ENAMELLING IRON AND STEEL. 



The process of Benjamin Baugh, of Chadwick, England, of 

 enamelling iron and steel, patented recently in the United States, 

 is as follows : 



Lay upon the surface of the. plate of the metal to be enamelled 



