Four inventions

Dear teachers and classmates, everyone:

In the vast history of the vast river, the 5,000-year history of the Chinese nation, writing the never-ending, pursuit of good and happy, shows the eternal search for democracy and prosperity. The long history and splendid civilization have never been interrupted. We know that the Chinese nation has four inventions. What do the four inventions mean?

The four inventions refer to the four inventions that have had a great influence on the world in ancient China. That is, papermaking, compass, gunpowder, movable type printing. This statement was first proposed by the British sinologist Joseph Needham and was inherited by many Chinese historians. It is generally believed that these four inventions have greatly promoted the development of politics, economy and culture in ancient China, and these inventions have been promoted. Various channels have been transmitted to the West, which has also had a great impact on the history of world civilization.

Then I will talk about papermaking. Papermaking is one of China's four major inventions, an outstanding invention in the history of human civilization. China is the first country in the world to raise silk and silk. The Han nationality working people and other silkworm cocoon silk woven silk, the remaining evil, sickness, etc. use the float method to make silk. After the float is over, there will be some residuals left on the banquet. When the number of floats is increased, the residual fluff on the mat will accumulate as a layer of fiber flakes, which are peeled off after drying and can be used for writing. The number of by-products of this floc is not much, and it is called Hess or Square in ancient books. This shows that the origin of Chinese Han papermaking has a relationship with silk.

Then let's talk about the improvement of papermaking, Cai Lun! Cai Lun improved the papermaking technique in the first year of the Eastern Han Dynasty.

He used bark, hemp and crepe, fish net and other raw materials, and the paper made by frustration, smashing, copying, baking and other processes is the origin of modern paper. This kind of paper, the raw materials are easy to find, they are very cheap, the quality is also improved, and they are gradually used. To commemorate Cai Lun’s achievements, later generations called this paper “Cai Hou Paper”.

After talking about papermaking, we will talk about gunpowder. The gunpowder was invented by the Han Chinese in the Sui and Tang Dynasties. It has been around for more than a thousand years. The study of gunpowder began in the ancient Taoist alchemy. The ancients refining the medicinal herbs for the sake of immortality. The purpose and motivation of alchemy are absurd and ridiculous, but its experimental methods still have merits, and finally led to gunpowder. invention.

Then let's talk about the compass. The compass is a simple instrument for judging the orientation, also known as the compass. The predecessor of the compass was Sinan, one of the four great inventions in ancient China. The main component is a magnetic needle that can be freely rotated on the shaft. The magnetic needle can be kept in the tangential direction of the magnetic meridian under the action of the earth magnetic field, and the north pole of the magnetic needle points to the geographical north pole. This performance can be used to distinguish the direction. Commonly used in navigation, geodetic, travel and military.

Then talk about movable type printing, the invention of movable type printing is a great technological revolution in the history of printing. The method of movable type printing is to first make a single-word embossed anti-text mode, then select the words according to the manuscript, arrange them in the dial, smear the ink, and then remove the stencil after printing, leaving it to be used again in the next typography. . In the Northern Song Dynasty, China’s Bi Sheng invented the birth of the movable type logo printing. He is the world's first inventor, than Germany J. The Gutenberg type printing book was about 400 years old.

Ok, thank you all for the end of my speech.

Guojia Center, Changchun City, Jilin Province, the sixth grade of the sixth class of six years: Liu Meizhen