154 AUTOBIOGRAPHY OF JOHN FRITZ
bottoms and stoppers. The floor for making them on, and an oven for drying them in, were arranged for economical working, with an eye to neatness.
The floor Une of the whole plant was on a level except the casting pit, which was about two feet below the floor Une. Tliis made it convenient for the men to pour into the moulds, and at the same time protected the men in case of accidental breaking out of the metal, wliich in the early liistory of the Bessemer process frequently occurred.
The converters were arranged in pairs, two on each side of the center of the buflding, with distance between them sufficient to allow work to be done in the pits for each pair of vessels without interfering with each other. The con¬ verters, wliich as before noted were in pairs, had a hydrauUc Uft between them, wliich raised the molten metal up to the height to pour into the vessel.
The engines of the mill for blowing and rolUng the steel were of the foUoAving dimensions:
The first Bessemer blowing engines had two steam cyl¬ inders thirty-six inches by sixty inches, coupled direct, with two blowing tubs forty-eight inches by sixty inches. The second pair of blowing engines (built later) had two steam cyUnders fifty-six inches by sixty-six inches, with two blowing tubs sixty inches by sixty-six inches. These engines were capable of maintaining forty pounds' air pressure. The smaUer blooming-null engine had a cylinder thirty-six inches by sixty inches, coupled direct, with two stands of three-high rolls thirty-two inches in diameter. The large blooming-mill engine cyUnder was sixty-five inches by ninety-six inches, with a ninety-ton flywheel, driving direct one stand of three-high rolls, forty-eight inches in diameter by ten feet long.
Both trains were suppUed with movable tables controUed by two levers at one point. The first rail train, twenty-