What are the ancient technologies in Hecheng District, Huaihua, Hunan?

1, papermaking. Flocculated paper and hemp fiber paper appeared successively in the Western Han Dynasty. The map paper unearthed in Fangmatan, Tianshui, Gansu Province is the earliest known paper in the world. Cai Lun, the eunuch of the Eastern Han Dynasty, improved papermaking in 105 and made plant fiber paper.

2. printing. During the Sui and Tang Dynasties, there were block-printed Buddhist scriptures, calendars and poems. The earliest block-printed products in the world were diamond sutra paper printed by China in 868. The engraving and printing industry in the Song Dynasty was very developed, with neat lettering. 1 1 In the middle of the century, movable type printing was invented by Bi Sheng in the Northern Song Dynasty, 400 years earlier than in Europe.

3. compass. During the Warring States period, people discovered the characteristics of magnetic permeability and invented "SiNa". In the Northern Song Dynasty, magnetic needles were used for guidance. Later, the magnetic needle was installed on the compass and made into a compass for navigation. During the Southern Song Dynasty, the compass spread to India, Arabia, Persia and other countries, which promoted the development of navigation in various countries and provided important conditions for opening up new routes and realizing global navigation.

4. gunpowder. Gunpowder was first mentioned in the book A Brief Introduction to Zhenyuan Er Lu in the Tang Dynasty, and it was used in the military at the end of the Tang Dynasty. In the Northern Song Dynasty, gunpowder was widely used in the military, and Tokyo set up a "widely prepared siege worker" to manufacture gunpowder and firearms. Song Renzong's book Wu Jing Zong Yao records many methods of making firearms. The "musket" was invented in Song Dynasty, and the appearance of tubular firearms opened a new stage in the history of human war.