1869.] 



Metallurgy. 



143 



atmosphere. In tlie bottom of the converter a number of short 

 cylindrical pots, lined with brick and fire-clay, are adjusted. Into 

 these pots a given weight of crude nitrate of soda of commerce is 

 put. The surface of the powder is levelled, and covered by a thick 

 circular plate of ca,st iron. One of these pots thus prepared having 

 been adjusted to the bottom of the cylinder, the converter is now 

 ready for use. At one side of the cylinder is a hopper, covered by 

 a loosely hinged flap of boiler-plate. This plate is raised, and the 

 ladle full of liquid cast iron is poured into the converter, and descends 

 upon the top of the cold cast-iron plate. The plate does not float 

 up nor become displaced, nor does any action become apparent 

 for some minutes, while the plate is rapidly acquiring heat from 

 the fluid iron above it, and the nitrate getting heated by contact 

 with it. 



Professor Miller, of King's College, thus describes the process : — 

 " In about two minutes a reaction commenced ; at first a moderate 

 quantity of brown nitrous fumes escaped ; these were followed by 

 copious blackish, then grey, then whitish fumes, produced by the 

 escape of steam, carrying with it, in suspension, a portion of the 

 flux. After the lapse of five or six minutes deflagration occurred, 

 attended with a roaring noise and a burst of a brilliant yellow flame 

 from the top of the chimney. This lasted for about a minute and a 

 half, and then subsided as rapidly as it commenced. When all had 

 became tranquil, the converter was detached from the chimney, and 

 its contents were emptied upon the iron pavement of the foundry. 

 These consisted of crude steel and of slag. The crude steel was in 

 a pasty state, and the slag fluid ; the cast iron plate had become 

 melted up and incorporated with the charge of molten metal. The 

 slag had a glassy blebby appearance, and a black or dark green 

 colour in mass." 



Professor Miller's report gives the following results of analysis 

 of three samples of metal produced at the Langley Mills under his 

 own observation : — 



Carbon 



Silicon, with a little titanium 



Sulphur 



Phosphonis 



Arsenic 



Manganese 



Calcium 



Sodium 



Iron (by difference) . . 



Cupolii. 

 Pig (4). 



2-830 

 2-950 

 0-113 

 1-455 

 0-041 

 0-318 



92-293 



100-000 



Crude. 

 Steel (7). 



•800 

 -2G6 

 ■018 

 -298 

 •039 

 •090 

 •319 

 •144 

 •0-26 



100-000 



Steel 

 Iron (8). 



0-993 

 0-149 

 traces 

 0-292 

 0-024 

 0-088 

 0-310 

 ti-aces 

 98^144 



100^000 



