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Pei Xiu

Pei Xiu
Chinese 裴秀
Style name
Chinese 季彥

Pei Xiu (224–271), courtesy name Jiyan, was a minister, geographer, and cartographer of the state of Cao Wei during the Three Kingdoms period of Chinese history, as well as the subsequent Jin Dynasty. Pei Xiu was very much trusted by Sima Zhao, and participated in the suppression of Zhuge Dan's coup. Following Sima Yan taking the throne of the newly established Jin Dynasty, he and Jia Chong had Cao Huan deprived of his position to accord to the will of heaven. In the year 267, Pei was appointed as the Minister of Works for the Jin Dynasty.

Pei Xiu outlined and analyzed the advancements of cartography, surveying, and mathematics up until his time. He criticized earlier Han Dynasty maps for their lack of precision and quality when representing scale and measured distances, although 20th century archeological excavations and findings of maps predating the 3rd century prove otherwise. There is also evidence that Zhang Heng (78–139 AD) was the first to establish the grid reference system in Chinese cartography.

Pei is best known for his work in cartography. Although professional map-making and use of the grid had existed in China before him, he was the first to mention a plotted geometrical grid reference and graduated scale displayed on the surface of maps to gain greater accuracy in the estimated distance between different locations. Historian Howard Nelson asserts that there is ample written evidence that Pei Xiu derived the idea of the grid reference from the map of Zhang Heng (78–139 AD), a polymath inventor and statesman of the Eastern Han period. Robert Temple asserts that Zhang should also be credited as the first to establish the mathematical grid in cartography, as evidenced by his work in maps, the titles of his lost books, and the hint given in the Book of Later Han (i.e. Zhang "cast a network of coordinates about heaven and earth, and reckoned on the basis of it").


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