144 BULLETIN 42, UNITED STATES NATIONAL MUSEUM. 



(I'i) Clay, used to slag off" oxido of in)u and to protect the metal during wtildiug. 

 (54411.) 



(1.3) Hammer scale, formed during the -welding froru the clay and oxide of iron. 

 (.54412.) 



(14) Crucible steel, finished bar ; made by heating and hammering the welded bar. 

 (54413.) 



(15) Hammer scale, produced by the oxidation of the metal while being hammered. 

 (.54414.) 



(16) Crucible steel, cold-rolled bar for drill rods, annealed. (.54415.) 



(17) Crucible steel, cold-rolled bar for drill rods, finished. (54416.) 



(18) Crucible steel, cold-rolled plate for rough stock. (54417.) 

 (ID) Crucible steel, cold-rolled plate, finished sheet. (5441^.) 

 (20) Crucible steel, sheet .004 inch thick. (54'J70.) 



THK CINCINNATI STEEL WOKKS. 



As being of bistorical interest tliree specimens of the first crucible 

 steel made in America, together with a wood engraving of the works, 

 are shown here. These works were built in 1832 near Cincinnati on 

 the Miami Canal, and the first steel was made in August of tlie same 

 year. The proprietors were Garrard Brothers, of whom Dr. AYm. Gar- 

 rard is still living at Fallston, Pennsylvania. (51130, 51131, 51132, 

 and 51133.) 



THE BESSEMER STEEL PROCESS. 



This process consists in blowing air through a bath of melted pig- 

 iron, whereby the silicon, carbon, most of the manganese, and a little 

 of the iron are oxidized, the heat furnished by their oxidation being 

 sufficient to keep the metal fluid, both during the process and also for 

 the time necessary after its close to finish and cast the steel. 



The conversion takes place in a vessel called a converter, the body 

 of which is egg shaped, with a suitable neck on top inclined about 30 

 degrees to the body, and a flat bottom wiih a number of openings for 

 the tuyeres through wliich the air is blown. Around the middle of the 

 converter is a heavy band carrying the trunnions on which it is sup- 

 ported and swings. Tke trunnion on one side is solid, and has a geared 

 wheel by which the converter is rotated. The trunnion on the other 

 side is hollow, and serves for the introduction of the blast. After 

 passing through the trunnion, the blast is delivered to a tuyere box 

 below the bottom, into which the tuyeres open. The tuyeres vary in 

 number from 10 to 15, are made of refractory material, and each tuyere 

 is perforated by ten to twelve small holes. The converters are made 

 with a shell of iron from three-quarters to 1 inch thick, lined with 10 

 to 12 inches of fire brick, and hold from G to 15 tons of metal. 



The action of the process is as follows : The converter lining being in 

 good condition and theconverterhotenough, it is turned downon its side, 

 and the charge of melted pig-iron run in. In this position the metal is 

 held entirely below the line of tuyeres, and the blast is therefore turned 

 otf, but as soon as all the charge is in, the vessel is brought back to the 



