gram) in the year Kangxi 7 (1668) which was heavier than those in many other provinces. Those responsible for the transportation of copper rarely made the mints in time, and while copper prices were rising daily the Ministry of Revenue still maintained a fixed rate of exchange between copper and silver causing many provincial mints to quickly lose money, while on paper they were still profitable. A mint was established in Tainan, Taiwan in the year 1689 but it didn't produce much cash coins and was closed down in 1692, for this reason Taiwanese Kangxi Tongbao coins tend to be very rare today. Kangxi Tongbao cash coins produced in the province of Yunnan are notably quite reddish in colour, there were at least seven different mints in existence in Yunnan Province during the Kangxi period. After the governor of the Yunnan and Guizhou found out that there were so much brass cash coins produced by the Yunnan Mints. The high supply of the brass cash coins had caused the price of the cash coins relative to silver to reduce. The government needed to pay 30% of cash coins instead of silver as military salary. This proved to be very inconvenient for the soldiers. This later caused disturbances to arise in the military. After the governor of these provinces put down the trouble, he urged the government to cease the production of cash coins in the province of Yunnan and to pay the soldiers exclusively in silver. All the Yunnan Mints were then closed down in the year Kangxi 28 (1689). Between the years 1674 and 1681 during the Revolt of the Three Feudatories the province of Yunnan was in the hands of the rebel Wu Sangui and later his grandson Wu Shifan who cast his own cash coins with their own inscriptions there, these cash coins didn't use the same mint marks as the Kangxi Tongbao. In 1684 the ratio of copper to zinc in the alloys in the Kangxi Tongbao cash coins was reduced from 70% to 60% all while the standard weight was lowered to 1 qián again and were known as Zhongqian (重錢), while the central government's mints in Beijing started producing cash coins with a weight of 0.7 qián known as Xiaoqian (小錢) or Qingqian (輕錢). The Kangxi Tongbao was officially fixed against silver with a ratio of 1000 Zhongqian per tael of silver in an