Industrial mining noise and smoke drive solitary prospectors into isolated, secret work.

Evidence

These mines, with their prolonged subterranean workings, their stamping and crushing mills, and the smelting works which have been established near them, fill the district with noise, hubbub, and smoke by night and day; but I had turned altogether aside from them into a still region, where each miner in solitude was grubbing for himself, and confiding to none his finds or disappointments. — Isabella L. Bird, A Lady’s Life in the Rocky Mountains, 211

Categorization

• XREF: Resonates with the soundscape material already in the reader’s notes — keynote industrial sound versus sought-out silence.