Those three old ships were found 'incidentally' by Luo Yan and Yue Qianqian when they were looking for the production site of the Menghuo Oil.
According to the recipe provided by Luo Yan, a large amount of sulfur, saltpeter, brown sugar, arsenic, and croton, etc., is required to produce Menghuo Oil. It just so happened that these old ships of Wang's Ship Company had all transported these goods two months ago, and in large quantities at that.
Yue Qianqian checked the clearance records of several ships and found that they would pause for half a day to a day when passing through Yizheng in Yangzhou to Dantu in Zhenjiang.
Therefore, both of them speculated that there is a private harbor, unrecorded by the authorities, either in Yizheng County northbank or Dantu County southbank, and so they inferred the place where Menghuo Oil was produced.
"I think it's more likely to be in Yizheng."
