茅元仪《武备志》卷240《郑和航海图》,所绘的很可能是七下西洋最后一次航程。这次航程的资料见于祝允明《前闻记》,其中提到的地名,和航海图的地名相当一致。比较航海图所载的地名,和郑和三位随员所写的游记(马欢《瀛涯胜览》、费信《星槎胜览》、巩珍《西洋番国志》)中的地名,得到结论:三部游记的地名,去除重复之后,共有29个,其中24个见于航海图。航海图所无的5个地名,很可能只是郑和船队分访问的地方。因此航海图的地名,代表的是船队主所到之处。通过对地理特征、建筑特征、物产商贸的考察,三部游记和航海图的内容显然可以互相补充,并且可以得出两个推断:第一,下西洋的动机,朝廷方面是宣扬国威,民间方面是宝船贸易。第二,综合三部游记和航海图的记载,都未能够带读者遍历下西洋诸国。
The navigational map in juan 240 of Mao Yuanyi's Wubei Zhi records most probably the last of Zheng He's series of seven expeditions to the "West Seas. " Details of this 7th expedition can be found in Zhu Yunrnings Qianwen Ji , and the place - names recorded in Qianwen ji are mostly the same as those recorded in the navigational map. It is also of interest to compare the place - names in the navigational map with those in the three travel books written by Zheng He's aides (Ma Huan's Yingya Shenglan, Fei Xins Xingcha Shenglan and Gong Zhens Xi yang Fanguo Zhi). Through such comparison, it is revealed that there are 29 different place - names (after elimination of duplicates) recorded in the three travel books, among which only 24 are recorded in the map. The omitted 5 place - names are probably those visited by the smaller, branch fleet. It can safely be concluded that the place - names in the map represent only those places visited by the main fleet. From geographical perspective, architectural perspective, and perspectives of commodities and commerce, the author compares the map and the travel books and come to realize their contents can supplement each other. He also makes two inferences based on the clues provided by these contents. Firstly, the purpose of Zheng He's expeditions were two - folded: the court aimed at extending the empire's power and influence, while the people, "treasure - ship commerce." Secondly, even all place - names in the map and the travel books put together do not account for all the places visited by the branch fleets.