As early as in the Shang Dynasty (16-11th century BC), the ancient Chinese had named the wind from four directions: Xia for the wind from the east, Wu from the south, Yi from the west, and Han from the north, and by the time of the Western Han Dynasty (206BC-24AD), names had been developed for 24 directions. During the Tang Dynasty (618-907), the names of the wind from 24 direction appeared in a book, together with examples to show how to decide the wind direction.

The wind observation instrument appeared quiet early in ancient China. During the Western Han Dynasty, a simple instrument named xian or huan was used to point to the wind direction, and during the Han Dynasty (206BC-220AD), Zhang Heng, a famous astronomer, invented two wind observation instruments -- Bronze Phoenix and Bronze Crow respectively -- that could move in the direction of the wind.

However, as the Bronze Phoenix and Bronze Crow were bronze-made, they were rather heavy and cumbersome. As a book depicted, "Only in the occasion of a heavy wind will it move." Therefore, they were gradually improved, and finally replaced by wooden or feather-made wind observation instruments.

As time went by, the ancient Chinese people realized that apart from the wind direction, the wind power also needed observation, as it was the main cause for destruction. So by the Tang Dynasty, people had began to evaluate the wind power by the destruction caused by the wind to ground objects. For example, first-grade wind would blow the tree leaves and second the twigs, while the third would shake the branches, and so on.

Author: Jessie