1 Cash - Qianlong Tongbao, Boo-san

The Board of Revenue operated satellite mints across the provinces, and Boo-san — the Manchu rendering of "Shanxi" used in mint nomenclature — was among the more productive of these provincial operations during the Qianlong reign. That reign lasted sixty years, the longest of any Qing emperor, and the sheer volume of cash coinage required to sustain it meant that quality control across provincial mints was inconsistent at best. Hartill 22.329 places this variety within a well-documented sequence, but individual specimens vary considerably in casting quality and alloy color.