Write an essay on the four great inventions of China

The Four Great Inventions

Papermaking:Papermaking is an important chemical process, and the invention of paper is a very valuable contribution made by China in the dissemination and development of human culture, and a major achievement in the history of Chinese chemistry.

Before paper was invented, oracle bones, bamboo slips and silk were the materials used for writing and recording in ancient times. However, due to the rapid economic and cultural development of the Western Han Dynasty, oracle bones and bamboo slips could not meet the needs of development, thus prompting the improvement of writing tools. At that time, people have begun to apply small pieces of silk made of paper, due to the ancient Han Dynasty paper is made of hemp and silk, coupled with the rough method of production, so the quality of paper is not very good. And hemp and silk have their own role, such as to use them as raw materials for paper making, it is bound to be very limited, and difficult to get rapid development to meet the requirements of cultural life on paper.

In the new objective situation, the emergence of the Eastern Han Cai Lun for papermaking to bring new breakthroughs, in the "Eastern Han Guanji" Volume II on the record: "Cai Lun, talented, loyal and prudent, each time the rest and bathing, closed to cut off guests, exposure to the field. Dengzuo Shangfang, making intention to use the bark of trees and my cloth, fishnet for paper. Yuanxing yuan played on, the emperor good its ability, since there is no use, the world salty Cai Hou paper". From the above, it seems that Cai Lun is the use of bark, rags, fishnet paper. Although there is paper before Cai Lun, but the raw material itself has great limitations, and Cai Lun's discovery of new raw materials to solve this problem. Because the rags, fishnets have long since ended their own tasks, become waste and used as raw materials, the paper industry has played a great role in promoting.

Printing: China's ancient working people after a long period of practice and research before the invention. Around 600 AD around the Sui Dynasty, people from the engraving of the seal to get inspired, in human history, the first invention of engraved printing.

Engraving printing is in a certain thickness of smooth wooden board, pasted on the transcription of the book manuscript, thin and almost transparent manuscript paper and the front of the board and paste, the word becomes a reverse body, the strokes are clearly recognizable. The engraver used a carving knife to cut away the part of the page without writing, and it became the font protruding yangwen, and the font concave inscription yinwen is very different. When printing, ink was applied to the raised typeface, then paper was overlaid on top of it, and the back of the paper was gently brushed, and the handwriting stayed on the paper. By the Song Dynasty, the engraving and printing business had reached its heyday. Engraving and printing played a significant role in the dissemination of culture, but there are obvious shortcomings. First, engraving is time-consuming and labor-intensive, second, it is inconvenient to store a large number of plates, and third, it is not easy to correct typos.

Bi Sheng, a civilian inventor in the Northern Song Dynasty, invented movable-type printing to improve on these shortcomings of engraved printing. Bi Sheng was an ordinary civilian intellectual in the middle of the Northern Song Dynasty, then known as Bu Yi. He summed up the rich practical experience of engraved printing through the ages, and after repeated tests, he made gum paste movable type in the Qingli years of Emperor Renzong of the Song Dynasty (1041-1048 A.D.), and implemented typesetting printing, which accomplished a major revolution in the history of printing, and this technology was spread to other countries about 200 years later, and played a role in promoting the development process of the world's civilization.

Gunpowder: one of the four great inventions of China. Gunpowder, as its name implies, is (medicine that catches fire). Its origin has a close relationship with alchemy, and it was unintentionally prepared by ancient alchemists during the alchemy.

It is a mixture of sulfur, saltpeter and charcoal, the first two of which are listed as important herbs in the first Chinese pharmacological text (Shennong Ben Cao Jing) written in the Han Dynasty. Is the gunpowder itself is also categorized as medicine, the Ming Dynasty Li Shizhen's (Materia Medica) said, gunpowder can cure sores and ringworm, kill insects, and dispel dampness and plague. The invention of gunpowder is the result of people's long-term practice of alchemy and pharmaceuticals, so far there has been more than a thousand years of history.

The end of the Tang Dynasty, gunpowder has been used for military. By the Song Dynasty, wars continued to promote the accelerated development of gunpowder weapons. The Northern Song government established a gunpowder workshop, has manufactured gunpowder arrows, artillery and other combustion performance-based weapons and (thunderbolt), (Zhentianlei) and other explosive weapons. Southern Song Dynasty in 1259 made a huge bamboo for the tube, filled with gunpowder (sudden fire gun). To the Yuan Dynasty and the emergence of copper cast fire system, known as (copper general). These are the explosion of gunpowder as the driving force of the weapon, in the war showed unprecedented power.

In the 12th and 13th centuries, gunpowder was first introduced into the Arab countries, and then spread to Greece and Europe and even all over the world. The progress of civilization of human society, economic and scientific and cultural development, played a driving role. The United States and France until the middle of the fourteenth century, the application of gunpowder and firearms records.