So they began a tour, among sights that made Jurgis stare amazed.  He wondered if ever he could get used to working in a place like this, where the air shook with deafening thunder, and whistles shrieked warnings on all sides of him at once; where miniature steam engines came rushing upon him, and sizzling, quivering, white-hot masses of metal sped past him, and explosions of fire and flaming sparks dazzled him and scorched his face.  Then men in these mills were all black with soot, and hollow-eyed and gaunt; they worked with fierce intensity, rushing here and there, and never lifting their eyes from their tasks.  Jurgis clung to his guide like a scared child to its nurse, and while the latter hailed one foreman after another to ask if they could use another unskilled man, he stared about him and marveled.

He was taken to the Bessemer furnace, where they made billets of steel—­a domelike building, the size of a big theater.  Jurgis stood where the balcony of the theater would have been, and opposite, by the stage, he saw three giant caldrons, 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 caldrons 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 theater 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.  A torrent of sparks swept all the way across the building, overwhelming everything, hiding it from sight; and then Jurgis looked through the fingers of his hands, and saw pouring out of the caldron a cascade of living, leaping fire, white with a whiteness not of earth, scorching the eyeballs.  Incandescent rainbows shone above it, blue, red, and golden lights played about it; but the stream itself was white, ineffable.  Out of regions of wonder it streamed, the very river of life; and the soul leaped up at the sight of it, fled back upon it, swift and resistless, back into far-off lands, where beauty and terror dwell.  Then the great caldron tilted back again, empty, and Jurgis saw to his relief that no one was hurt, and turned and followed his guide out into the sunlight.

They went through the blast furnaces, through rolling mills where bars of steel were tossed about and chopped like bits of cheese.  All around and above giant machine arms were flying, giant wheels were turning, great hammers crashing; traveling cranes creaked and groaned overhead, reaching down iron hands and seizing iron prey—­it was like standing in the center of the earth, where the machinery of time was revolving.