He went first and she followed into the deafening hubbub of whistling, amid clouds of steam peopled by human shadows moving busily.
The passages were very narrow and there were obstacles to step over, holes to avoid, passing carts to move back from.

She couldn't distinguish anything clearly or hear what Goujet was saying.
Gervaise looked up and stopped to stare at the leather belts hanging from the roof in a gigantic spider web, each strip ceaselessly revolving.

The steam engine that drove them was hidden behind a low brick wall so that the belts seemed to be moving by themselves.

She stumbled and almost fell while looking up.
Goujet raised his voice with explanations.

There were the tapping machines operated by women, which put threads on bolts and nuts.