1 Cash - Tongzhi Tongbao; Boo-gung; privately cast

Privately cast cash coins represent a persistent grey market within the official Qing monetary system. The Board of Revenue and Board of Works mints held nominal monopolies on copper-alloy cash production, but enforcement was chronically inconsistent, and entrepreneurial foundries — particularly in Hunan, Guangdong, and Jiangxi — filled gaps during periods when official supply collapsed. By the Tongzhi reign, those gaps were enormous: the Taiping Rebellion had destroyed or disrupted dozens of provincial mints, and Boo-gung (the Beijing Board of Works mint) was itself operating erratically.

The brass composition here, rather than the officially mandated copper-zinc-lead alloy in fixed ratios, is a reliable indicator of private origin.