介绍四大发明的人和四大发明的时间英语作文
The earliest reference to magnetism in Chine literature is found in a 4th century BC book called Book of the Devil Valley Master (鬼谷子): "The lodestone makes iron come or it attracts it."
The earliest reference to a magnetic device ud as a "direction finder" is in a Song Dynasty book dated to AD 1040-44. Here there is a description of an iron "south-pointing fish" floating in a bowl of water, aligning itlf to the south. The device is recommended as a means of orientation "in the obscurity of the night." However, the first suspended magnetic needle compass was written of by Shen Kuo in his book of AD 1088.
For most of Chine history, the compass that remained in u was in the form of a magnetic needle floating in a bowl of water. According to Need ham, the Chine in the Song Dynasty and continuing Yuan Dynasty did make u of a dry compass, although this type never became as widely ud in China as the wet compass.
The dry compass ud in China was a dry suspension compass, a wooden frame crafted in the shape of a turtle hung upside down by a board, with the loadstone aled in by wax, and if rotated, the needle at the tail would always point in the northern cardinal direction. Although the 14th century European compass-card in box frame and dry pivot needle was adopted in China after its u was taken by Japane pirates in the 16th century (who had in turn learned of it from Europeans), the Chine design of the suspended dry compass persisted in u well into the 18th century.
The prevailing academic connsus is that gunpowder was discovered in the 9th century by Chine alchemists arching for an elixir of immortality. By the time the Song Dynasty treati, Wujing Zongyao (武经总要), was written by Zeng Gongliang and Yang Weide in AD 1044, the various Chine formulas for gunpowder held levels of nitrate in the range of 27% to 50%. By the end of the 12th century, Chine formulas of gunpowder had a level of nitrate capable of bursting through cast iron metal containers, in the form of the earliest hollow, gunpowder-filled grenade bombs.
In AD 1280, the bomb store of the large gunpowder arnal at Weiyang accidentally caught fire, which produced such a massive explosion that a team of Chine inspectors at the site a week later deduced that some 100 guards had been killed instantly, with wooden beams and pillars blown sky high and landing at a distance of over 10 li (~2 mi. or ~3.2 km) away from the explosion.
By the time of Jiao Yu and his Huo longjing in the mid 14th century, the explosive potential of gunpowder was perfected, as the level of nitrate in gunpowder formulas had rin to a range of 12% to 91%, with at least 6 different formulas in u that are considered to have maximum explosive potential for gunpowder. By that time, the Chine had discovered how to create explosive cannonballs by packing their hollow shells with this nitrate-enhanced gunpowder.
Further information: Science and technology of the Han Dynasty
Papermaking has traditionally been traced to China about AD 105, when Cai Lun, an official attached to the Imperial court during the Han Dynasty (202 BC-AD 220), created a
sheet of paper using mulberry and other bast fibres along with fishnets, old rags, and hemp waste. However a recent archaeological discovery has been reported from near Dunhuang of paper with writing on it dating to 8 BC.
While paper ud for wrapping and padding was ud in China since the 2nd century BC, paper ud as a writing medium only became widespread by the 3rd century. By the 6th century in China, sheets of paper were beginning to be ud for toilet paper as well. During the Tang Dynasty (AD 618-907) paper was folded and wn into square bags to prerve the flavor of tea. The Song Dynasty (AD 960-1279) that followed was the first government to issue paper currency.
The Chine invention of Woodblock printing, at some point before the first dated book in 868 (the Diamond Sutra), produced the world"s first print culture. According to A. Hyatt Mayor, curator at the Metropolitan Muum of Art, "it was the Chine who really discovered the means of communication that was to dominate until our age." Woodblock printing was better suited to Chine characters than movable type, which the Chine al
so invented, but which did not replace woodblock printing. Western printing press, although introduced in the 16th century, were not widely ud in China until the 19th century. China, along with Korea, was one of the last countries to adopt them.
The intricate frontispiece of the Diamond Sutra from Tang Dynasty China, AD 868 (British Muum)
Woodblock printing for textiles, on the other hand, preceded text printing by centuries in all cultures, and is first found in China at around 220, then Egypt in the 4th century, and reached Europe by the 14th century or before, via the Islamic world, and by around 1400 was being ud on paper for old master prints and playing cards. In another analysis Hyatt Mayor states that "a little before 1400 Europeans had enough paper to begin making holy images and playing cards in woodcut. They need not have learned woodcut from the Chine, becau they had been using woodblocks for about 1,000 years to stamp designs on linen."
