Papermaking - Cai Lun, gunpowder - alchemist, printing - Bi Sheng, compass - Zhang Heng
Compass
Compass, called Sinan in ancient times, its main components are A magnetic needle mounted on a shaft. The magnetic needle can rotate freely under the action of the natural geomagnetic field and remain in the tangent direction of the magnetic meridian. The north pole of the magnetic needle points to the north magnetic pole. This performance can be used to identify the direction.
Gunpowder
It is a substance that can burn rapidly and regularly under the influence of appropriate external energy, and at the same time generate a large amount of high-temperature gas. In the military, it is mainly used as propellant for bullets and artillery shells, propellant for rockets and missiles, and energy for other driving devices. It is an important part of ammunition. An outstanding achievement in the history of human civilization. Gunpowder, with its lethality and deterrence, has brought human beings peace of mind and security, and has become one of the important inventions of human civilization.
Papermaking - Cai Lun
In ancient China, working people made silk from top-grade silkworm cocoons, and the remaining bad cocoons and diseased cocoons were used to make silk floss using the floc method. After bleaching the catkins, there will be some residual catkins left on the bamboo mat. When the wadding is bleached a lot, the remaining wadding on the bamboo mat will accumulate into a thin layer of fiber, which can be peeled off after drying and can be used for writing. The by-product of this kind of floating catkins is not large in quantity, and it is called Hehe or Fang Xu in ancient books. This shows that the origin of papermaking in ancient China is closely related to silk wadding.
Movable type printing
Movable type printing is an ancient printing method that was invented by the working people of ancient China after long-term practice and research. First, make a reverse character model of the single characters, then select the characters according to the manuscript, arrange them in the type plate, apply ink and print, and then remove the character model after printing, leaving it to be used again in the next printing.
Extended information:
Invention process
Block printing
Block printing is a smooth wooden board with a certain thickness, pasted on the copy. The neat manuscript has a thin and almost transparent front side and a wooden board, so the words become reversed and the strokes are clearly legible. The engraver used a carving knife to cut off the unwritten part of the page, resulting in a convex font, which is completely different from the concave font on the stele. When printing, ink is applied to the raised lettering, then the paper is placed over it, and the back of the paper is gently wiped so that the writing remains on the paper.
In the Song Dynasty, the engraving and printing industry reached its heyday. Block printing has played a major role in the spread of culture, but it also has obvious shortcomings: first, engraving blocks is time-consuming, labor-intensive, and material-intensive; second, it is inconvenient to store large quantities of books; third, it is difficult to correct typos.
Movable type printing
Bi Sheng, a civilian inventor in the Northern Song Dynasty, summarized the rich practical experience of woodblock printing in previous dynasties. After repeated trials, it was made during the Qingli period of Emperor Renzong of the Song Dynasty (1041-1048 AD). He invented movable clay type and implemented typesetting and printing, completing a major revolution in the history of printing.
Bi Sheng's method is as follows: use clay to make blanks with the same specifications, engrave reverse single characters on one end, and the height of the protrusions of the characters is the same as the thickness of the edge of a copper coin, and use fire to harden them. Become a single clay type. In order to meet the needs of typesetting, several or even dozens of commonly used characters are generally prepared for use when they are repeated in the same edition. If you encounter uncommon words that are not commonly used, you can just make them and use them if you have not prepared them in advance.
Movable type printing
In order to facilitate word picking, the clay movable type was placed in wooden grids according to rhyme and labeled with paper strips. When typing, use a framed iron plate as the base, apply a layer of agent made of a mixture of rosin, wax and paper ash on it, and then pick out the required clay movable type one by one and put them into the frame. When a frame is filled up, it becomes a version. Then it is baked with fire. When the agent is slightly melted, a flat plate is used to flatten the words. After the agent cools and solidifies, it becomes a version. When printing, just brush ink on the pattern, cover it with paper, and apply a certain amount of pressure.
In order to print continuously, two iron plates were used, one for brushing and the other for typesetting, and the two plates were used alternately. After printing, use fire to bake the agent, shake it gently with your hand, and the movable type can fall off the iron plate, and then put it back into the original wooden grid according to the rhyme, so that it can be used again next time.
Bi Sheng also experimented with wooden movable type printing. Due to the uneven density of the wood texture, difficulty in engraving, deformation of the wooden movable type after being exposed to water, and difficulty in separating when stuck together with chemicals, Bi Sheng Not adopted.
Bi Sheng's clay type printing method is not easy if you only print two or three copies. If you print hundreds or thousands of copies, the work efficiency is extremely impressive. It can not only save a lot of manpower and material resources, but also greatly increase the speed of printing. And the quality is much superior to block printing.
Movable type plate making just avoids the shortcomings of engraving. As long as enough single movable type is prepared in advance, plates can be made at any time, which greatly speeds up the plate making time. After the movable type plate is printed, it can be dismantled and the movable type can be reused. Moreover, the movable type takes up less space than the engraving plate and is easy to store and keep. In this way, the superiority of movable type is shown.
The idea of ??printing with movable type has been around for a long time. Qin Shihuang unified the country's weights and measures, and used wooden stamps to print the edict with four crosses on the pottery measuring vessels. Archaeologists believe that "this is Chinese movable type" The beginning of typography, but although he invented it, it was not widely used." Ancient seals also provided some inspiration for movable type printing.
Baidu Encyclopedia - Movable Type Printing