ON THE MECHANICAL PROPERTIES OF STEEL. 101 



scription of Avhich we venture to transcribe from a pamphlet published by the 

 proprietors of the Heaton process. 



" The furnace (which is a common cnpola) is charged with pig-iron and 

 coke, and fired in the usual waj% and the iron when melted is drawn off into 

 a ladle, from which it is transferred to the converter. 



"The converter is a wrought-iron pot lined with fire-brick. In the bottom 

 is introduced a charge of crude nitrate of soda, usually in the proportion of 

 2 ewt. per ton of converted steel, usually but not invariably diluted with 

 about 25 lb. of siliceous sand. This charge is protected or covered over with 

 a close-fitting perforated iron plate weighing about 100 lb., the diameter of 

 the plate being about 2 feet. The converter, with its contents, is then 

 securely attached, by moveable iron clamps, to the open mouth of a sheet- 

 iron chimney, also lined for 6 feet with fire-brick, and the melted iron taken 

 in a crane ladle from the cupola is poured in. The subsequent part of the 

 process is thus described by Professor Miller. 



" ' 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, a violent deflagration occurred, attended with a loud roaring 

 noise and a burst of 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 com- 

 menced. "When all had become tranquil, the converter was detached from 

 the chimney, and its contents were emptied on to the iron pavement of the 

 foimdry. 



" ' The crude steel was in a pasty state and the slag fluid ; the cast-iron 

 perforated plate, which was placed as a cover to the converter, bad become 

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

 a glassy or blebby appearance, and a dark or green colour in mass.' Professor 

 Miller proceeds to detail the subsequent parts of the process, and the results 

 of his analysis of some of the products. 



" * A mass of crude steel from the converter was then subjected to the 

 hammer. 



" ' About 4| ewt. of the crude steel was transferred to an empty but hot 

 reverberatory furnace, where in about an hour's time it was converted into 

 four blooms, each of which was hammered, rolled into square bars, cut up, 

 passed through a heating-furnace, and roUed into rods varying in thickness 

 from 1 inch to five-eighths of an inch. 



" ' Three or four ewt. of the crude steel from the converter was transferred 

 to a reheating furnace, then hammered into flat cakes, which, when cold, were 

 broken up and sorted by hand for the steel melter. 



" ' Two fireclay pots, charged with a little clean sand, were heated, and 

 into each 42 lb. of the cake steel was charged ; in about six hours the melted 

 metal was cast into an ingot. 



" ' Two other similar pots were charged with 35 lb. of the same cake steel, 

 7 lb. of scrap steel, and 1 ounce of oxide of manganese. These also were 

 poured into ingots. 



" ' The steel was subsequently tilted, but was softer than was anticipated. 



" ' These residts are on the whole to be considered rather as experimental 

 than as average working samples. 



" ' I have therefore made an examination of the following samples only : — 



No. 4. Crude Cupola Pig. No. 8. Eolled Steely Iron. 



No. 7. Hammered Crude Steel. No. 5. Slag from the converter. 



