What were the great inventions in ancient China?

In the 4th century BC, China invented cast iron? . At least in the 4th century BC, China used blast furnaces to cast iron. In addition, high-temperature coal can be supplied as fuel from the 4th century, or earlier.

In the late feudal society, cast iron was widely used as agricultural tools (such as plows and mirrors), salt pans, iron cannons and artistic castings. A.D. 10 century has been able to cast extra-large iron castings weighing 50 tons (such as Cangzhou Iron Lion in Hebei Province). After the Five Dynasties, iron buildings increased, such as the Northern Song Pagoda in Dangyang, Hubei.

2、

Papermaking is an important invention of working people in ancient China. There are two forms: mechanical and manual. The mechanism is continuous on the paper machine. The paper pulp suitable for paper quality is diluted to a certain concentration with water, and is preliminarily dewatered in the wire section of a paper machine to form a wet paper sheet, then dewatered by pressing, and then dried into paper.

Manually use a frame with bamboo curtain, polyester net or copper net to copy the fibers dispersed and suspended in water into wet paper pages, press and dehydrate them, and then dry or dry them into paper.

3. Compass

Compass is the result of China ancient working people's understanding of magnet magnetism in long-term practice. As one of four great inventions of ancient china, its invention has played an inestimable role in the development of human science, technology and civilization.

In ancient China, the compass was first used for rituals, etiquette, military affairs and divination, and to determine the orientation when looking at geomantic omen. It is often used in navigation, geodesy, tourism and military affairs. The invention of the compass with physical direction indication has three parts, namely Sina, compass and magnetic needle, all of which belong to the invention of China.

4, gunpowder

It is a substance that can burn quickly and regularly under the action of appropriate external energy, and at the same time produce a large number of high-temperature gases. Militarily, it is mainly used as the propellant of bullets and shells, the propellant of rockets and missiles and the energy source of other driving devices, which is an important part of ammunition.

Outstanding achievements in the history of similar civilizations. Because of its lethality and shocking power, gunpowder is one of the important inventions of human civilization, which has brought the functions of relieving armistice and security defense to mankind.

Step 5 print

Engraving printing was invented in the Tang Dynasty and was widely used in the middle and late Tang Dynasty. Song Renzong and Bi Sheng invented movable type printing, which marked the birth of movable type printing. He was the first inventor in the world, about 400 years before Johannes Gutenberg invented movable type printing, which marked the birth of movable type printing. ? [

Printing is the forerunner of modern human civilization, which creates conditions for the wide spread and exchange of knowledge. Printing first spread to Korea, Japan, Central Asia, West Asia and Europe.

Baidu encyclopedia-printing

Baidu encyclopedia-gunpowder

Baidu encyclopedia-compass

Baidu encyclopedia-papermaking

Baidu encyclopedia-cast iron