四大发明英文PPT

China was the first country in the world to make proper paper. Paper made during the Western Han Dynasty (202 BC-16 AD) has been found in Gansu Province, Xi'an and other places in Shanxi Province as well as Xinjiang. A further development of paper is credited to Cai Lun of the Eastern Han (25220). He used plant fiber such as tree bark, bits of rope, rags and worn-out fishing nets as raw materials. In 105, Cai presented the first batch of paper made under his supervision to the Han emperor, who was so delighted that he named the material "Marquis Cai's paper".
The earliest reference to a magnetic device used 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 itself 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.
Mariner’s compass
In the Northern Song Dynasty the mariner’s
compass was invented. It was made by putting a magnetic needles on a wooden disk called luopan. With the invention of compass, people are no longer determine direction by the position of the sun in the day-time and the stars at night
The importance of the invention of paper can hardly be exaggerated. It had a great significance to cultural progress not only in China but throughout the world.
Pointing-to-the-South-Fish
It is a piece of thin iron sheet cut into the shape of a fish ,magnetized in a geomagnetic field and put into water, floating and lying north - to – south .This was the earliest compass
• Gunpowder
• The gunpowder is made of niter, sulfur and charcoal three kinds of materials mixing.
• 火药
• 火药是由硝石、硫和木炭 三种原料混合制成的。
• In the Tang Dynasty, the gunpowder begins to be applied to the military affairs. • People utilize the throwing stone machine, light the gunpowder bag and throw out, burn the enemy, this is the most primitive cannon.
The dry compass used 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 lodestone sealed 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 use was taken by Japanese pirates in the 16th century (who had in turn learned of it from Europeans), the Chinese design of the suspended dry compass persisted in use well into the 18th century.
There are 3 kinds of compass
Primitive compass
Pointing - to - the - South – Fish
Mariner’s compass
Primitive compass
It is in the shape of spoon cut from an natural magn来自百度文库tite
For most of Chinese history, the compass that remained in use was in the form of a magnetic needle floating in a bowl of water. According to Needham, the Chinese in the Song Dynasty and continuing Yuan Dynasty did make use of a dry compass, although this type never became as widely used in China as the wet compass’
• 唐朝，火药开始应用到军事上。 • 人们利用抛射石头的抛石机，把火药包点 着以后，抛射出去，烧伤敌人，这是最原 始的火炮。
Handgun from the Yuan dynasty, circa 1300s.
Hemp wrapping paper, China, circa 100 BC
Compass
Seals(relief & intaglio)
→→→
Block printing
The first method of printing in China was the seals—in relief or intaglio. Then, in the 6th century block printing was invented by combining the two methods used for seals and stone rubbings.
Four Great Inventions
great contributions of the Chinese people to the world’s civilizations
小组成员：陈咏雪 李勐 张薇 李雪菁
Paper
Printing
Gunpowder
Compass
The earliest Chinese characters were inscribed on bones,
By the end of the 11th century , On the basis of printing using carved blocks in the Tang Dynasty, a man called Bi Sheng of the Northern Song Dynasty invented movable type printing in the 1040s. Bi's printing consisted of four processes: making the types, composing the text, printing and retrieving the movable types. Economical and convenient, the use of these types brought about a revolution in printing. In the mideighth century, printing began to be introduced into Korea and Japan in the East and Egypt and Europe in the West, playing a great role in the cultural development of the world.
tortoise shells and bronze wares in the Shang Dynasty and later, written on silk, bamboo and wood. The earliest Chinese books were made from flat strips of bamboo or wood, inscribed and then threaded together. They were heavy and bulky, inconvenient for reading and carrying.