From the time of the first emperor there was a need for warships in support of military campaigns in the basins of the Yangtze and the Xi (near Canton). These fortified, and sometimes armored, ships were initially powered through oars manned by soldiers. But the specific needs of riverborne military operations led to a very curious invention. It was in 784, under the Tang, that a prince named Li Gao developed warships powered by paddlewheels.[456] This invention may well have come from the 5th century.
This type of boat sees major development on the Yangtze, pushed by a great naval architect named Gao Xuan, at the beginning of the 12th century when the Song retreat into south China. Paddlewheels are mounted on the sides of the vessel; the number of them is variable, but could be as many as eleven on each side, often with a large wheel on the stern in front of the rudder. The wheels are powered by pedalboards, and Chinese authors mention that these ships can attain very high speeds.[457]
The ocean-going junk, precursor of the modern sailboat
We have seen that the technological basis of modern sailboats appeared in China during the Han period, 2nd century AD. The elements of this technology were the axial rudder and the modern sail. Navigation develops widely on the Yangtze, in its immense estuary, and along the southeast coasts of China. The marking of the coasts with beacons
develops under the Yuan. Junks having multiple masts appear from the 3rd century.
The large ocean-going junk reaches maturity in the 9th century. This is a very large ship having three or four masts, sometimes even six. In the Song period it can exceed 100 meters in length and can carry several hundred people. One passenger, our Tangiers traveler Ibn Battuta, describes it as follows:
“The large junk has twelve sails, the others (i. e. smaller junks) have up to three. The sails are of bamboo, woven together into mats, they are never lowered but always turn according to the wind direction. When the boat is at anchor, the sails remain hoisted, buffeted by the wind. The crew comprises a thousand men: six hundred sailors and four hundred soldiers: archers, shield carriers, crossbowmen who fire naphtha. [….] On the ship there are four decks with bunks, cabins and salons for the merchants.”[458]
In the 11th century the compass appears on Cantonese junks; before it had been used only by astrologists who assured the correct celestial orientation of dwellings. The compass makes seafaring navigation far easier. The large junks navigate on the Sea of China and the Indian Ocean toward Korea, the south of India, and the Persian Gulf. The port of Canton is recognized since the time of the Qin Dynasty; it hosts a cosmopolitan community of sailors and merchants from everywhere. Fuzhou, somewhat further north, is another large port. Hangzhou, a port and city that, in the 13th century, earns the admiration of both Marco Polo and Ibn BattUta when they visit, is exceptionally prosperous in the period after the retreat of the Song into south China.
At the beginning of the Ming Empire, grand maritime expeditions are launched on all seas to celebrate the new rulers and the eviction of the detested Mongols. These expeditions represent the apogee of navigation in imperial China. Between 1405 and 1433 seven expeditions follow one after another, involving an immense fleet of 62 large junks nearly 130 m long and 50 meters wide, in addition to a number of smaller boats. These expeditions are as much diplomatic as commercial, with destinations of Indochina, Java, Sumatra, the south of India, Ceylon, Hormuz in the Persian Gulf, Jeddah in the Red Sea, Aden and the eastern coast of Africa, and perhaps even Mozambique.[459]
But the decline of seafaring navigation in China begins in the 16th century. This decline results from the quasi state monopoly established by the Ming, who authorize only large official expeditions. This decline coincides also with military setbacks in struggles against the Mongols in the north, and with a pullback of the Ming civilization taking refuge in a sort of defensive posture within the borders of China. Western sailors of the 17th and 18th centuries find the Chinese coasts to be infested with pirates, and witness a population turning its back to its coasts.
