He was taken to the Bessemer furnace, where they made billets of steel⁠—a dome-like building the size of a big theatre. Jurgis stood where the balcony of the theatre would have been, and opposite, by the stage, he saw three giant cauldrons, big enough for all the devils of hell to brew their broth in, full of something white and blinding, bubbling and splashing, roaring as if volcanoes were blowing through it⁠—one had to shout to be heard in the place. Liquid fire would leap from these cauldrons and scatter like bombs below⁠—and men were working there, seeming careless, so that Jurgis caught his breath with fright. Then a whistle would toot, and across the curtain of the theatre would come a little engine with a carload of something to be dumped into one of the receptacles; and then another whistle would toot, down by the stage, and another train would back up⁠—and suddenly, without an instant’s warning, one of the giant kettles began to tilt and topple, flinging out a jet of hissing, roaring flame. Jurgis shrank back appalled, for he thought it was an accident; there fell a pillar of white flame, dazzling as the sun, swishing like a huge tree falling in the forest.