Home > Civilization > Application of Other Navigation Knowledge
Large   |  Small

Application of Other Navigation Knowledge

Diagram of the twenty-four seasonal division points by which the solar year is divided under the traditional Chinese calendar according to the sun's apparent movement along the ecliptic. 
The ancient Chinese people accumulated ample knowledge on weather forecast and composed it into a series of weather proverbs, which were handed down by word of mouth. Those living on the seaside, based on the geographical and climatic characteristics of the seas and rivers, also summed up a set of weather forecast proverbs viable for oceangoing voyages.

There was a record on correct weather forecasting experience in the Dream Creek Notes by the famous scientist Shen Kuo of theNorthern Song Dynasty(960-1127):

The wind in winter is gradually fostered, so preparations can be made prior to navigation; but usually, there are abrupt gusts in summer, which may endanger sailing vessels. To avoid such sea perils, the businesspeople in the water towns in the south of theYangtze Riverwould get up very early in the morning to observe the sky. If there was a clear and bright moon and twinkling stars, but no clouds on the horizon, it was suitable for seagoing. By 9:00-11:00 a.m., the boats would be anchored to withstand the gusts.

There were also a great many methods and tools for observing wind direction in ancient China.

During theShang Dynasty(16-11th BC), people used a ribbon attached to a flag for wind direction observation, giving rise to the concept of "wind from four sides."

Thebronzeinstruments for wind observation during theHan Dynasty(206BC-220) - the "Bronze Phoenix" and "Bronze Crow" -- were the earliest wind observation apparatus in the world. As was recorded in scientific books, there was a rotating device at the bottom of the "Bronze Phoenix," which would rotate in the direction of the wind. The "Bronze Crow" of theEastern Han Dynasty(25-220), shaped like a crow, was installed on astronomical observatories and could also move with the wind.

The bronze-made wind observation crow of the Han Dynasty
During theJin Dynasty (265-420), light and handy wooden wind observation instruments took the place of the bronze ones. A wood-carved crow, with a flag on the tail, was placed atop a long pole or on theroof, and could rotate on four sides. If the wind blew from the south, the crow's head would turn south while the flag would turn north. This demonstrated that the ancient people, through long-term wind observation, deepened their knowledge on monsoons.

By the Song Dynasty (960-1279), Chinese navigators had already mastered the law of monsoons, and applied it to navigation. One source, on ships sailing to the Southeast Asia along the Pacific route, said: "ships leave (China) in November or December, taking advantage of the north wind, while coming (from Southeast Asia) in May or June, with the south wind."

However, the weather at sea changed constantly apart from the regular monsoons. To solve this problem, ancient navigators accumulated ample weather-forecast experiences, and took advantage of the Chinese sails, such as the rotational sails, to guarantee the use of wind power under various conditions. During theSouthern Song Dynasty(1127-1279), Chinese sailors invented a zigzag route for ships to move forward against the wind.