At present, the traditional view is that the ancestor of compass appeared in the Warring States Period. Compass is used in military affairs, production, daily life, topographic survey and other aspects, especially in navigation. The application of compass in navigation has a gradual development process.

gunpowder

gunpowder was invented by alchemists in the process of alchemy.

the dragon gun is like a rocket launcher. There are two small rockets at the head and tail of the dragon gun. When the small rockets are ignited, the rocket launcher will rise, and then other rockets in the rocket launcher will be ignited and fired at the enemy, usually to fight with water.

printing

in the song dynasty, Bi Sheng invented movable type printing.

blocks with the same specifications are made of clay, and one end is engraved with words, which is called a movable type printing table. When printing, the movable type printing table is arranged according to the content of the article, fixed on the chassis coated with adhesive to become a movable type plate, then painted with ink, and then printed with paper.

papermaking

in the eastern Han dynasty, people began to use paper as a writing tool in large quantities after eunuch Cai Lun improved the method of making paper. Paper-making is an important event in the history of human civilization. It took more than 1 years for this advanced technology to spread to Europe.