1 Cash - Qianlong Tongbao, Boo-jyi

The Boo-jyi mint — romanized from the Manchu name for the Board of Revenue facility in Beijing — was one of two central imperial mints operating directly under court supervision, the other being the Board of Works mint across the city. During Qianlong's reign, both mints were periodically ordered to adjust alloy ratios and coin weight in response to copper shortages driven by sustained demand from a population that roughly doubled over the eighteenth century. The brass composition of this issue, rather than the traditional bronze, reflects those supply pressures.