Jim Siebold 收集世界地图40年，把所有地图按年代整理，发表在网站。从西元前6000年到文艺复兴（1490-1800）http://www.myoldmaps.com/ 

这是他的序言一页：http://www.myoldmaps.com/about-this-websitethis-web.html

他自称为：

An amateur cartographic historian. Over the past 45 years I have tried to accumulate information relating to my favorite old maps, resulting in over 6,000 pages over 200+ monographs and my website www.myoldmaps.com since 1994.

关于《坤舆万国全图》，他做了比较详细的阐述，附有关其他地图比较，共23页。该文最后引用了我的结论。

http://www.myoldmaps.com/renaissance-maps-1490-1800/441-ricci.pdf 

Dr. Siu-Leung Lee theorizes that the world map Kun Yu Wan Guo Quan Tu, a map completely labeled in Chinese and previously thought to be the works of the Italian Jesuit Matteo Ricci in 1602, is incompatible with the authorship of Matteo Ricci or European cartographers. The following summarizes Dr. Lee’s observations.

[此处列举我的证据，从略，见Siebold 网站。]

By Dr. Lee’s account, according to a statement and the historical background of place names on the map, it is constructed between 1428 and 1430, more than 60 years before Christopher Columbus’ first voyage. Martino Martini’s Novus Atlas Sinensis also supports the capability of Chinese cartography in Ming dynasty. The loss of original Chinese documents, translational errors, and Ming politics have kept this secret for the past 600 years, until the details of this map are publicly available. According to Dr. Lee the entire history of cartography and Age of Exploration should be revised to include the pioneering voyages (1405-1433) and cartographical development led by Zheng He, the Chinese Admiral.

作者还没有引用我最近的论文：

China Mapped America Before 1430 (2017年国际地图学双年会论文）2017年7月4日

https://www.proc-int-cartogr-assoc.net/1/67/2018/ica-proc-1-67-2018.pdf  

这是西方地图学最权威会议。我的论文利用地球物理数据比较《坤舆万国全图》与其他同时期西方世界地图，完全推翻利玛窦按照西方地图学测绘《坤舆万国全图》的论点。世界交通史必须更正。

我演讲后，纽约总图书馆地图部专家AQ Wright 在推特发的评语，“目前最佳演讲！”，随后立刻被纽约博物馆点赞：

明代环球航海-证据与现代意义 明代海上丝路与美洲 （2017年国际地图学双年会论文中文增订版) http://blog.sciencenet.cn/blog-1674084-1191990.html  （本篇列入比较重要参考）

李兆良

2020.6.13