The Four Symbols in Ancient Astronomy The ancients divided the twenty-eight constellations into four directions: east, north, west, and south. The seven constellations in each direction were imagined as four animal images, which are called the Four Symbols.

The Eastern Qisu resembles a giant dragon flying in the night sky in spring and early summer, so it is called Dong Cang Long; the Northern Qisu resembles snakes and turtles appearing in the night sky in summer and early autumn, so it is called Northern Xuanwu; the Western Qisu looks like a tiger leaping out in late autumn and early winter.

The night sky in the cold winter and early spring is like a red bird, so it is called the Western White Tiger; the Southern Qisu looks like a flying red bird, appearing in the night sky in the cold winter and early spring, so it is called the Southern Red Bird.

The moon is the most prominently described object among the natural objects mentioned in ancient poems and articles.

Its other names can be divided into: (1) Because the first moon is like a hook, it is called silver hook or jade hook.

(2) Because the crescent moon is like a bow, it is called jade bow or bow moon.

(3) Because the full moon is like a wheel, a disk, or a mirror, it is called a golden wheel, a moon wheel, a silver disk, a jade disk, a gold mirror, or a jade mirror.

(4) Because it is said that there are rabbits and toads in the middle of the moon, it is called Silver Rabbit, Jade Rabbit, Golden Toad, Silver Toad, and Toad Palace.

(5) Because it is said that there is a laurel tree in the moon, it is called Guiyue, Guilun, Guigong and Guipo.

(6) Because it is said that there are two palaces, Guanghan and Qingxu, in the middle of the moon, they are called Guanghan and Qingxu.

(7) Because it is said that the god who drives the moon is named Wangshu, so the moon is called Wangshu.

(8) Because it is said that Chang'e lives in the middle of the moon, the moon is called Chang'e.

(9) Because people often compare beautiful women to the moon, they call the moon Chanjuan.

Ancient Geography Rivers In many ancient articles, they specifically refer to the Yangtze River and the Yellow River.

For example, "Hongmen Banquet": "The generals fought in Henan, and the ministers fought in Hebei." "On Passing the Qin Dynasty": "Then practice Huahua City, because the river is a pond." "Essentials for Sisters" "The first tomb was in Hang, the river is wide and the river is deep", here

"Jiang" refers to the Yangtze River, and "河" refers to the canal.

Xihe is also called Hexi, the area west of the Yellow River.

For example, "The Biography of Lian Po and Lin Xiangru": "Meeted at Mianchi outside the Xihe River." "On Passing Qin": "So the Qin people handed over and took the outside of the Xihe River." Jiangdong is east of the Yangtze River.

For example, Li Qingzhao's poem says: "I still miss Xiang Yu and refuse to cross Jiangdong." "Battle of Chibi": "With the help of my father and brother, I separatized Jiangdong." Jiangzuo is Jiangdong.

The ancients regarded east as left and west as right.

"The Meeting of Heroes and Jiang Qian's Plan": "Immediately, an order was sent to summon the heroes from Jiangzuo to meet Ziyi." Jiang refers to the area south of the Yangtze River.

"Battle of Chibi": "The heroes on the river surface, Xian returned to them." Jiangnan is the general name for the south of the Yangtze River, and the area it refers to varies from time to time.

Bai Juyi's poem goes: "The south of the Yangtze River is good, and the scenery is familiar to me." Wang Anshi's poem goes: "The spring breeze is green again on the south bank of the river. When will the bright moon shine on me again?" Huaizuo east of the Huai River.

"Yangzhou Slow" "The famous capital of Huaizuo, the best place in Zhuxi", Yangzhou is to the east of Huai River.

Shandong, as its name suggests, is on the east side of the mountains.

However, it should be noted that the "mountain" in "Shandong" can refer to several different mountains such as Mount Wei, Mount Huashan, Mount Taihang, Mount Tai, etc., and the regions they refer to are not the same.

The following is "Shandong" with Weishan as the standard.

For example, "Han Shu" once mentioned that "Shandong produces prime ministers, and Shanxi produces generals."

"Hongmen Banquet": "When Pei Gong lived in Shandong, he was greedy for wealth." "On the Passage of Qin": "The heroes of Shandong then merged and destroyed the Qin clan." Guandong in ancient times refers to the area east of Hanguguan or Tongguan, and in modern times it refers to the area east of Hangu Pass or Tongguan.

Northeastern region east of Shanhaiguan.

Cao Cao's "Hao Li Xing": "There are righteous men in Guandong, who raised troops to fight against the evil forces." Refers to the area east of Tongguan.

Guanxi refers to the area west of Hangu Pass or Tongguan Pass.

"Battle of Chibi": "Ma Chao and Han Sui are still in Guanxi to avoid future troubles." The scope of Guanzhong refers to different areas. The ancients used to call the area west of Hangu Pass Guanzhong.

"Hongmen Banquet": "Pei Gong wanted to be king in Guanzhong and made his son and infant his prime minister." "On the Passage of Qin": "The first emperor's heart was that Guanzhong was solid." Chronology There are four main types of chronology in ancient my country: (1) The chronology of the years when princes came to the throne.

The year is calculated based on the number of years the prince has been in power.

"The Biography of Lian Lin": "In the sixteenth year of King Zhao Huiwen, Lian Po was the general of Zhao." (2) Year number chronology.

Emperor Wu of the Han Dynasty began to have reign titles.

After that, every emperor who ascended the throne had to change the Yuan Dynasty and mark the year with the year name.

Such as the "Ten Years of Yuanhe" in "Pipa Xing".

(3) Calculation of the stems and branches.

For example, "Tombstone Notes of Five People": "I still remember that Duke Zhou was arrested, and I looked forward to it in the third month of Dingmao." (4) The year number uses both stems and branches.

When recording the year, the emperor's year number is placed first, and the stems and branches are listed behind.

"Nuke Zhou Ji" "Apocalypse Renxu Autumn Day" Month-keeping Method There are three main types of moon-keeping methods in ancient my country: Ordinal month-keeping method.

For example, in "Collecting Herbs": "Like March flowers on the plains, there are April flowers in the deep mountains." Earthly Branches Monthly Method.

The ancients often referred to the twelve earthly branches as twelve months, and a specific word "build" was added before each earthly branch.

For example, Du Fu's poem "The Thatched Cottage": "The deserted village is built on the moon, and the old man's house is the only tree." "Jianzi Month" refers to the eleventh month of the lunar calendar according to the Zhou Dynasty's lunar calendar.

The law of seasons and months.

For example, "Nineteen Ancient Poems": "The cold weather is coming in Mengdong, and the north wind is so miserable.