Air ufed in the BlaJi-'Furnace. i i^ 



therto wtneflTed. The idea was ingenious, and, in its appli- 

 fcation to the manufafturfe of caft iron, original ; but the 

 Whole train of fafts^ laid down in thi^ and former papers, as 

 to the eftefts of a fuperabundant quantity of oxygen, was 

 overlooked. The event proved in the nioft cornplete manner, 

 and on a great fcale, the pernicious effe£ls of moifture. The 

 furnace gradually became cooled where the fteam entered ; 

 the heat, fet free by the dccompyfition of the water and the 

 difengagcment of oxygen, increafed to an alarming pitch a 

 confiderable way up the furnace; the quality of the iron be- 

 came brittle, and as white In the frafture as filver; the in- 

 troduction of the ileam was ftill continued, the defcending 

 tnaterials werd inftantly robbed of their heat to facilitate the 

 decompofition of the water, and by-and-by the furnace clofed 

 entirely over, and the experiment ccaifed *. 



This experiment, performed in a furnace i8 feet high, is a 

 complete proof that heat is difengaged from bodies while thev 

 pafs from the fluid to the aeriform Hate. The firft inftarit of 

 the difcharge of fleam, a very con(iderable portion c^ heat 

 Would be withdrawn from the fufing materials and united to 

 the water; This, in its turn, would be ignited to whitenefs, 

 and decompofed upon the metals and cokes, in a fuperior re- 

 gion of the furnace. The procefs continuing for feveral hours, 

 the materials at the tuyre were at laft fo completely deprived 

 of the caloric by the continual torrent of fteam, that they loll 

 fluidity, cooled rapidly, and at lall became black. Had an- 

 other aperture for fteam and for air been opened above thefe, 

 now entirely fliut up by the confolidated materials, the fame 

 eHe6ls would have been produced ; the immenfe quantity ot 

 caloric, difengaged by the decompofition of the ignited water, 

 would now approach nearer to the top of the furnace, an- 

 other llratuni of fufing materials would again become con- 

 folidated, till in the end the whole furnace would be fet fall 

 from top to bottom. From the introdu6lion of fteam into 

 lire blaft-furnace, either as fuch, or under a fuperior degree 



'' The refjieflablc Riid ingctiinus auihor of this cxperiii^.'.'.it is among 

 the firft in the iron trade wlio devotes a liberal and Scientific education to 

 the improvement of this favourite branch : from his fituation, talents, and 

 *p[ior"inity, murh may h«; expc^ed. 



a 4 of 



