Yong-le: Year 20, Month 8, Day 14
30 Aug 1422
Wang Yan-guang, a clerk of Bo-bai County in Guang-xi, advised: " The four counties of Bo-bai, Bei-liu, Lu-chuan and Xing-ye in Yu-lin Subprefecture annually transport to the battalions of Wu-zhou, Ping-le and so on over 90,000 shi of grain. At this time, this area's stores have a surplus and it is possible to reach Lian-zhou by water from Yu-lin. From Lian-zhou it is then possible to reach Xin-an in Jiao-zhi. The journey is quite short. If Bo-bai and the other counties in Yu-lin transport grain to Lian-zhou storehouse and then the Jiao-zhi military personnel and civilians are ordered to transport it themselves from there, the transport of grain from Lian-zhou County to Xin-an and Wan-ning in Jiao-zhi will be very convenient." The Heir Apparent approved this.
Zhong-yang Yan-jiu yuan Ming Shi-lu, volume 14, page 2341