Chinese four great inventions compass,paper making printing gun power

China's four great inventions namely papermaking, printing, gunpowder and the compass, which made tremendous contributions to the world's economy and the culture of mankind. They are also the symbols of China as one ancient civilization country.
Paper Making
Before paper was invented, the ancient Chinese carved characters on pottery, animal bones and stones, cast them on bronzes, or wrote them on bamboo or wooden strips and silk fabric. These materials, however, were either too heavy or too expensive for widespread use. The invention and use of paper brought about a revolution in writing materials and greatly contributed to the spread of civilization.
In 105 A.D. Cai Lun, a eunuch during the Eastern Han Dynasty, invented paper from worn fishnet, tree bark and cloth. These raw materials could be easily found at a much lower cost so large quantities of paper could be produced. Eastern Han Dynasty paper found in Wuwei, Gansu Province carried words which were still clearly decipherable. The paper was thin, soft with tight texture.
The technique of paper making spread to Korea in 384 AD. A Korean Monk then took this skill with him to Japan in 610 AD. During a war between the Tang Dynasty and the Arab Empire in 751AD the Arabs captured some Tang soldiers and paper making workers. Thus paper making spread to Arab. In the 11th Century the skill was carried to India when Chinese monks journeyed there in search of Buddhist sutras. Through the Arabs, Africans and Europeans then mastered the skill. The first paper factory in Europe was set up in Spain. In the latter half of the 16th century, this skill was brought to America. By the 19th century, when paper factories were set up in Australia, paper making had spread to the whole world.
Printing
Inspired by engraved name seals, Chinese people invented carved block printing around 600 AD. The skill played an important role in the Song Dynasty but its shortcomings were obviously. It was time-consuming to engrave the blocks, not easy to store, and not easy to revise errors.
On the basis of printing using carved blocks in the Tang Dynasty, Bi Sheng of the Northern Song Dynasty invented movable type printing in the 1040AD, which ushered in a major revolution in the history of printing.
Bi's printing consisted of four processes: making the types, setting up type, printing and retrieving the movable types. According to Dream Stream Essays, Bi Sheng carved individual characters on squares of sticky clay, then baked them make clay type pieces. When composing a text, he put a large iron frame on a piece of iron board and arranged the words within the frame. While one plate was being printed, another plate could be composed. After printing, the movable types were taken away and stored for future use. Movable type printing has a very important position in the history of printing, for all later printing methods such as wooden type, copper type and lead type printing invariably developed on the basis of movable clay types. Bi Sheng created movable type printing more than four hundred years earlier than it was invented in Europe.
Gunpowder
The birth of gunpowder was quite accidental. It was first invented inadvertently by alchemists while attempting to make an elixir of immorality. It was a mixture of sulphur, saltpeter, and charcoal. At the end of the Tang Dynasty, gunpowder was being used in military affairs. The first prescription for gunpowder appeared in 1044, much earlier than the earliest (1265) gunpowder-making instructions recorded in Europe. By the Song Dynasty (960-1126), gunpowder was in extensive use. The Song army also used cannons flame throwers, which were bamboo tubes filled with gun power.
In the 12th and 13th centuries, gunpowder spread to the Arab countries, then European countries, and finally all over the world.
Compass
According to ancient records, natural magnets were employed in China as direction-finding devices. This led to the first compass, called a sinan (south-pointing ladle) during the Warring States Period. In the Han Dynasty compasses consisted of a bronze board on which 24 directions were carved and a rod made from a natural magnet. Such devices were in use until the eighth century.
In the Song Dynasty, Shen Kuo described the floating compass, suspended in water, a technique which minimized the effect of motion on the instrument. This enabled the compass to be used for sea navigation for the first time. The invention of the compass promoted maritime undertakings, and its use soon spread to the Arab world, and thence to Europe.