Guo Shoujing (Kuo Shou-Ching)

SUBJECT AREA: Canals, Civil engineering

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b. 1231 China

d. 1316 China

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Chinese mathematician, astronomer and civil engineer.

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First, from 1262, he was engaged in hydraulic-engineering works for Kublai Khan. He began astronomical and calendrical investigations in 1276, and became the greatest astronomer of the Yuan dynasty. He perfected interpolation formulae (a method of finite differences) and was the founder of the study of spherical trigonometry in China; this was applied to the circles of the heavenly sphere. He planned the Ji Zhou, the summit section of the Grand Canal through the Shandong foothills, in 1283. Although the canal had to await further improvement before it could become fully effective, it was nevertheless the world's first successful entirely artificial summit canal.

Guo Shoujing was responsible for the construction of the Tong Hui He (Channel of Communicating Grace) canal with twenty lock gates in 1293, in addition to the overhaul of the entire Grand Canal. He constructed a number of devices, including 40 ft (12 m) gnomons in 1276, with which he made some of the most accurate measurements of the sun's solstitial shadows, the results of which were collected in a book that is now lost. Between 1276 and 1279 he also constructed at least one water-driven mechanical escapement clock with sophisticated jack work, and the Beijing observatory and its equipment.

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Further Reading

J.Needham, Science and Civilisation in China, Cambridge: Cambridge University Press, 1959–1971, vols III, pp. 48–50, 109–10, 294, 296, 299, 349, 350; IV. 2, pp. 504–5; IV.

3, pp. 312ff., 319, 355; Heavenly Clockwork, 1960, pp. 134, 136ff., 159, 160, 163;

Clerks and Craftsmen in China and the West, 1970, pp. 2, 5, 9–10, 16, 96, 398.

LRD