Pei Xiu - Pei Xiu The Cartographer

Pei Xiu The Cartographer

Further information: History of cartography#China

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").

The preface to Pei Xiu's written work was preserved in the 35th chapter of the Book of Jin, which is the official history for the Jin Dynasty and one of the Twenty-four Histories. It was written in the Book of Jin that Pei made a critical study of ancient texts in order to update the naming conventions of geographic locations described in old texts. His maps —drawn upon rolls of silk — were presented to the Jin emperor, who preserved them in the court's archives. Pei Xiu's maps have since been lost, decayed, or destroyed. Yet the oldest existing terrain maps from China date to the 4th century BC, found in a Qin State tomb of modern Gansu province in 1986. Han Dynasty era maps from the 2nd century BC were found earlier in the 1973 excavation of Mawangdui.

In 1697, the Qing Dynasty cartographer Hu Wei reconstructed Pei's maps in his Yugong Zhuizhui (A Few Points in the Vast Subject of the Yu Gong). Modern scholars have also used Pei's writing to reproduce his works, and historians such as Herrmann have compared Pei to other great ancient cartographers such as the Greek cartographer Ptolemy (83–161).