Is Li the first person in the world to grade the wind?

Li is the first person in the world to grade the wind.

Yi Sizhan is an astrological masterpiece by Li Chuanshi, a Taoist priest in the Tang Dynasty. Li believes that astrology has its inherent foundation. Natural phenomena are unpredictable, and careful observation has certain regularity. Some changes of people can be induced by different kinds, and people are the most typical.

At present, our discrimination of wind power is entirely based on the classification of wind power in Yi Sizhan, and Li divides it into 8 grades according to the influence and harm degree of wind power on trees. Description in the book: 1 level moving leaves, singing at level 2, shaking branches at level 3, falling leaves at level 4, breaking twigs at level 5, breaking big branches at level 6, breaking trees and flying sand at level 7, and uprooting trees at level 8.

He also believes that the size of the wind is different from the distance from its source. The stronger the wind, the farther it blows. The preparation and method of anemometer are described in the Law of Waiting Wind in Volume 10, which is of high scientific value even now.

Li's academic achievements:

Li learned and studied astronomy, calendars, arithmetic and astronomical instruments in Taishi Museum, and gained a lot. Soon he wrote to Emperor Taizong, suggesting to reorganize the armillary sphere, and Emperor Taizong readily agreed.

After seven years of Zhenguan, I finally made a new armillary sphere, that is, a celestial ecliptic instrument cast in bronze. The ancient double armillary sphere was changed into three armillary spheres, six external instruments, three middle instruments and four internal instruments. Before that, the armillary sphere was only equivalent to four instruments and six instruments. This instrument can measure the longitude and latitude of the ecliptic, equator and horizon.

Emperor Taizong named Li Chengwulang and ordered him to put the armillary sphere in Ninghuige. In the process of developing the armillary sphere, he studied the development and characteristics of the ancient armillary sphere, wrote seven volumes of Fa Xiang Zhi, and commented on the difference between the gains and losses of the previous armillary sphere.

In the fifteenth year of Zhenguan, Li was Doctor Taichang and in the eighteenth year he was Tai Shicheng. When I wrote the Book of Jin, I wrote three chronicles, astronomy, law calendar and five elements, and summarized the research results of predecessors, which was particularly exquisite.