The nautical chart of Zheng He was handed down from generation to generation, which was included in Wu Bei Zhi by Mao Yuanyi, an author in the late Ming Dynasty.

Zheng He's Nautical Chart was originally called Zibao Shipyard Sailing Out of Longjiang Pass and Reaching Foreign Countries. The original picture was a long scroll in a straight line, and it was changed into a book style when it was included in Wu Beizhi. From right to left, there were 20 pictures, 40 pictures of * * *, and finally two pictures of "crossing the ocean and leading the stars" were attached. The whole map of Zheng He's Nautical Map records a vast area, stretching tens of thousands of kilometers from Nanjing Treasure Shipyard to the east coast of Africa, in which more than 530 place names are drawn, including more than 30 countries and regions in Asia and Africa.

Extended data:

Zheng He's Nautical Map is the earliest existing nautical atlas in the world. Compared with the most representative Portland chart in the west at the same time, Zheng He's Nautical Chart has a wide range and rich contents. Although its mathematical accuracy is lower, its practicability is better than Portland chart. British Joseph Needham pointed out in his book "History of Science and Technology in China" that Mills and Blagdon had made a careful study on the accuracy of nautical charts in China. Both of them were familiar with the entire coastline of Malay Peninsula, and they spoke highly of the accuracy of nautical charts in China.

References:

Baidu Encyclopedia-Zheng He's nautical chart