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What can I see clearly? (in kind)
Maps have become very popular in modern people's daily life, even to the point where they have to bring maps when they go out. So, when did China start to have maps?

Some people speculate that the origin of maps predates that of words. Because the original image is like a painting, it faithfully draws mountains, roads and trees into the map, which is a guide for hunting and going out to work or travel.

For thousands of years, the fairy tale of "Hebo dedicating a picture" has been widely circulated among Chinese people. Legend has it that Hebo was moved by Dayu's spirit of "three don't enter the house". Hebo is the water god of the Yellow River. In order to control water, I traveled all over the mountains and swamps. Suddenly, one day, he saw Hebo coming from the Yellow River and offering a big bluestone. When I looked carefully, it turned out to be a water control map. With the help of the map, Yu successfully managed the water. Although the "legend" can't confirm the specific time of the origin of the map, it shows from the side that our ancestors used the map about 4 thousand years ago.

According to historical records, maps were born in China as early as 1000 BC. There is a record in Hanshu Jiaoyi Record: "Yu received the gold of nine shepherds and cast Jiuding, such as Kyushu". There is a saying in Zuo Zhuan: "I cherish Xia Fang's virtue, and pay tribute to Jin Jiu for grazing, casting a tripod and making statues, so that people can know the treachery of God." It means that in the heyday of the Xia Dynasty, people from far away painted landscapes, features and animals, and the chief of Kyushu gave Yu Xia maps and some metals as gifts. He took the "Gold of Nine Animals" and threw the paintings drawn by people from far away on a tripod so that people could distinguish various things from these paintings. The article "Get everything ready" clearly shows that this is a picture of a shepherd and a traveler. Unfortunately, the original logistics spread to the Spring and Autumn Period and the Warring States Period more than 2,000 years ago, but it was lost because of the war.

According to Zhu, a thinker in Song Dynasty, the classic Classic of Mountains and Seas in later generations evolved from Jiuding Map in Xia Dynasty, and it is also an original map. Mountains, water, animals, plants, minerals, etc. They are all drawn on the "Five Zangs and Three Classics Map" in the classic mountain and sea classics, and marked with the directions, which is a relatively standardized map form. It can be said that China had an original map in the Xia Dynasty.

Where is the oldest existing map in the world?

The oldest existing map in the world is a map carved on pottery in the city of Gasu Cuba (in today's Iraq) in northern Babylon, Cuba. The picture shows the city of Babylon, Tigris River and Euphrates River in Cuba. It was carved in about 2500 BC, about 4000 years ago.

What kind of map is the earliest existing physical map in China?

1986 The map unearthed from Qin Tomb in Fangmatan, Tianshui, Gansu, China, is the earliest physical map discovered in China so far.

Seven maps were unearthed at Fangmatan. Draw them on four boards of equal size. According to experts' argumentation, it was drawn in the late Warring States period around 300 BC, more than 300 years earlier than the Huahe map in the forest of steles in An, and about 300 years earlier than the map of the Western Han Dynasty 1973 unearthed in Mawangdui, Changsha, Hunan. The map includes the Weishui River basin in the northwest of Boyang Town, Tianshui, Gansu Province, and a part of the water system around Fangmatan. There are 82 notes on place names, rivers, mountains and forest resources in the map. Surprisingly, today, tributaries of Weihe River and many canyons in this area can be found in this map, which is consistent with the records in Shuijing Note. All kinds of trees marked in the picture, such as thistle, cypress, Phoebe bournei, pine, etc., have basically the same plant distribution and natural environment in today's Weishui area. Experts believe that the excavation of this map provides physical evidence for the developed map documents in China in the pre-Qin period.

What is the earliest existing military map in the world?

The earliest military map found in the world was 1973. In February, China, the colored silk-painted garrison map was unearthed from Mawangdui No.3 Han Tomb.

This picture is on a piece of silk, the scale is about1100000, and the picture is divided into three colors: red, blue and black. Residential areas are represented by black circles, mountains are represented by black "mountain" symbols, rivers are represented by cyan, and roads are represented by scarlet. These geographical elements are all shown on the second plane, and the positioning is accurate. The first floor highlights the military deployment: the red triangle castle represents the base camp, the red and black borders represent the stations, command points and checkpoints of the nine armies, and the red lines distinguish the boundaries of the defense zones. The hierarchy is clear and clear at a glance.

According to textual research, this painting was painted by Wendi in Chinese more than 2 100 years ago. At that time, Zhao Tuo, the king of South Guangdong, attempted to split one side and undermine national unity. This map reflects the war situation at that time and the deployment of troops of both sides. Using maps as the general's sacrificial objects fully embodies the importance attached by ancient military strategists to maps.

Foreign military experts believe that this "garrison map" proves that China's military science reached a high level two thousand years ago, which is of great reference value to the study of China's ancient military.

What is the earliest monograph on calculation in China?

Measurement and calculation are twin brothers. With the development of measurement technology in China, related calculation theories and methods have also been developed. During the Three Kingdoms period (3rd century A.D.), the first calculation monograph, Archipelago Calculation, appeared.

The Archipelago Calculations was written by Liu Hui, a mathematician in the Three Kingdoms Period. When he took notes for nine chapters of arithmetic, he wrote a volume of errors and attached it to the book. Li Jiang, a mathematician in the Tang Dynasty, listed the heavy differences and named them "Calculating Classics on the Island", which was listed as one of the "Ten Books of Calculating Classics" in ancient China. The nine examples in this book all involve the problem of height measurement and its calculation. These nine examples are: measuring the height of the island (lookout island), measuring the height of pine trees on the mountain (lookout pine), measuring the size of the city (lookout city), measuring the depth of ravines (lookout valley), measuring the height of towers on the ground (lookout tower), measuring the width of rivers (lookout wave mouth), measuring the depth of clear water pools (lookout Qingyuan) and measuring the width of lakes (from the mountain) These methods boil down to one point, that is, gravity difference measurement. Gravity difference measurement is a theory and method to measure the height, distance and depth by using simple measuring tools such as moment, watch and rope, according to the proportional internal relationship between the corresponding sides of similar right triangle. Before Liu Hui, Zhao Shuang made a daily height map and put forward gravity difference's measurement theory for the first time when he was annotating the Classic of Weekly Parallel Calculations. In the book Calculation of Islands, Liu Hui skillfully used gravity difference's theory to put forward a variety of specific measurement and calculation methods, which popularized gravity difference's measurement theory.

Island Calculation is an enduring monograph on calculation. Gravity difference's surveying theory and method revealed in detail became the basic basis of ancient surveying, and built a bridge to realize the leap from direct surveying (step or quantity) to indirect surveying. Until today, the theory and method of weight difference measurement still have reference significance in some occasions.

Who first put forward the concept of "earth"

Some people think that the concept of "earth" was first put forward by Aristotle, an ancient Greek scholar. After textual research, Plato, Aristotle's teacher, was the first person to put forward this concept. Around the 4th century BC, Plato thought from the viewpoint of natural philosophy that the most perfect form in the universe is spherical, so the earth where people live should also have the most perfect form, and the earth can only adapt to the requirements of "cosmic harmony" and "number" if it is spherical.

At that time, Plato participated in an academic organization in ancient Greece, which regarded his research results as all within the organization and kept them strictly confidential, so Plato's view of "the earth" did not spread for a long time. Later, his disciple Aristotle accepted the teacher's point of view and boldly published it on the basis of observing a large number of natural phenomena such as solar eclipses.

What is the earth like and how do people know it?

With the rapid development of science and technology, human beings have become more and more aware of the face of the earth where they live. However, people's understanding of the true face of the earth has gone through a long process.

In ancient times, due to the underdevelopment of science and technology, there were many legends and myths about the appearance of the earth, and human beings could only know the earth through simple observation and imagination. For example, when the ancients in China observed that "the sky is like a vault", they put forward the view that "the sky is round". According to the fact that the land they live in is surrounded by the sea, the ancient westerners thought that "the land is like a disk, floating on the boundless ocean". From about the 8th century BC, Greek scholars tried to understand the earth through natural philosophy. In the second half of the 6th century BC, Pythagoras put forward the idea that the earth is a sphere. Two centuries later, Aristotle also realized that the earth is spherical according to natural phenomena such as solar eclipse, and accepted his teacher Plato's point of view and published the concept of "earth", but none of them were proved reliably.

Until the 3rd century BC, Eratosthenes, an Alexandria scholar, initiated the meridian arc measurement method, actually measured the latitude difference to estimate the radius of the earth circle, and confirmed the "theory of the earth circle" at the earliest. Later, Zhang Heng, an astronomer in the Eastern Han Dynasty, made a complete exposition of "Huntian Theory" in "Notes on Hunyi" and realized that the earth is a sphere. But he said in the astronomical work Lingxian that the sky is round and the earth is flat. All these show that people's understanding of the shape of the earth was still very unclear at that time.

From the 6th century, under the shackles of western religions, people did not continue to advance along the road of understanding the material world, but went backwards. On the contrary, science and technology in China developed rapidly at this time. In the 1920s, Nangong, the official governor of a group of eminent monks in the Tang Dynasty, said that it was the first time in the world to measure the distance and latitude difference in the Henan Plain by arc measurement. It is concluded that the arc length of the earth meridian 1 degree is 132.3 km, which is 2 1 km larger than the modern accurate value. After that, Arabia also carried out fruitful arc measurement in the 9th century. This proves that the earth is spherical. However, due to the limited range of human activities at that time, its true form has not been tested by practice. It was not until 1522, more than 400 years ago, that the navigator Magellan led his fleet from Spain, sailed westward, passed through the Atlantic Ocean, the Pacific Ocean and the Indian Ocean, and finally returned to Spain, which proved that the earth was indeed a sphere.

However, human understanding of the earth did not end there. With the development of science and technology and the formation and enrichment of geodesy, there are more and more ways and means for people to observe and understand the shape of the earth. Triangulation, gravity measurement, astronomical measurement and so on are all important means. Newton, a modern scientist, carefully studied the rotation of the earth and came to the conclusion that the earth is an ellipsoid with equatorial uplift and flat poles, shaped like an orange. By the end of 1950s, the artificial earth satellite was successfully launched. Through satellite observation, the asymmetry between the northern and southern hemispheres was found. The distance from the South Pole to the center of the earth is 40 meters shorter than the distance from the North Pole to the center of the earth. Therefore, some people describe the earth as a pear.

Above, the understanding of the earth is still based on local data and indirect means. If only people could stand far away from the earth and watch it! 1On July 20th, 969, when the astronauts of the American moon landing spacecraft Apollo 1 1 landed on the moon, they saw the round blue earth, just like watching the moon on the earth. According to previous data and photos taken by astronauts, scientists think it is best to regard the earth as an "irregular sphere".

At this point, has human understanding of the shape of the earth been completed? Not yet. This is because the earth is too big! It has been running and changing.

The earliest people and methods to estimate radius of the earth in the history of the world.

In the 3rd century BC, Eratostheny, an Alexandria scholar, first estimated the length of radius of the earth by applying the relationship between the arc length S on the circumference, the corresponding circumferential angle △φ and the radius R in geometry.

He found that at noon on the summer solstice in Sene, Egypt, the sun was shining directly at the bottom of the well, while at the same time in Alexandria, the sun was 7.2 degrees south. It is concluded that the latitude difference between Alexander and Cheney is △φ = 7.2. Based on the travel time of the commercial camel caravan at that time, it is estimated that the distance between the two places is about 5000 Stady (1 Stady is equivalent to157.5m). According to the formula,

R=S/△φ

According to calculation, radius of the earth R is about 6,300 kilometers. Under the conditions at that time, it was quite difficult to calculate this figure. This is not much different from the data measured later with advanced instruments and equipment. Eratosthenes's contribution is that he pioneered the meridian arc measurement method and confirmed the "Earth Circle Theory" with the estimated results for the first time.

How is the "flat ground theory" proved?

In the second half of the 6th century BC, scholars have put forward the view that the earth is a sphere. 1522 Magellan successfully sailed around the world, which attracted people's attention to the shape of the earth. However, it was not until the late17th century that Newton, Huygens and other scholars put forward the oblateness theory according to the theory of universal gravitation, and thought that the earth kept rotating around its axis, and its shape must be an ellipsoid with slightly oblateness poles.

The slightly flat north and south of the earth can be confirmed by arc measurement. Because the meridian ellipse near the pole has a small curvature, the radius of curvature is large. The meridian ellipse near the equator has a large radius of curvature and a small radius of curvature. The same arc length 1 on the meridian ellipse must be s north > s south. During the period of 1683 ~ 17 18, French Cassini and his son made an arc survey in meridian circle. Because of the large measurement error, it is concluded that the earth is a long and narrow sphere from north to south, which is contrary to Huygens' inference according to the laws of mechanics. In order to solve this problem, the French Academy of Sciences sent two investigation teams to Peru and Lapland in northern Europe in 1735, thus confirming the theory of border areas. And two parameters are used to represent the shape and size of the earth, namely, the long radius α and the short radius B. This is a leap in human understanding of the earth, but this leap has gone through 2400 years.

The gravity survey well proves the theory of earth flatness: low gravity at low latitudes means that the ground is far from the center of the earth; Where the latitude is high, the gravity value is large, indicating that the ground is close to the center of the earth. Therefore, the earth is a flat sphere.

What is "painting six bodies"

Six-body surveying and mapping is the six methods of surveying and mapping put forward by Pei Xiu, a cartographer in Jin Dynasty.

Pei Xiu (AD 224 ~ 27 1) was a well-known person in Hedong (present-day Shanxi). When Emperor Wu of Jin lost the lawsuit, he became prime minister. He checked the old drawings left by Wei according to "the Sixth Army passed by, the region was far and near, the mountains and rivers were dangerous, the roads were circuitous and straight". Due to the rough drawing of the old map and the change of place names, he compiled the earliest atlases in China-Regional Map of Gong Yu and Local Map of Topography with the help of Guest Scenery. He summed up the experience of cartography in the past and put forward six principles of cartography, namely, "six aspects of cartography": one is "fraction", which reflects the ratio of area to length and width, that is, today's scale; The second is "quasi-observation", which is used to determine the mutual orientation relationship between landforms and features; The third is "Daoli", which is used to determine the distance between the two roads; The fourth is "competition", that is, relative elevation; The fifth is "square evil", that is, the fluctuation of ground slope; The sixth is "circuitous", that is, the conversion between the fluctuation of the site and the distance on the map. Pei Xiu believes that the six aspects of cartography are interrelated and extremely important in map making. If the map only has graphics and no scale, it is impossible to compare and measure the distance between the field and the map; If you draw according to the scale, regardless of accuracy, then the accuracy of the map here is ok, and there will be deviations elsewhere; With direction and no road, we don't know the distance between residential areas on the map, just like the barrier between mountains and seas can't be connected; With distance, we can't measure the slope of Fugui Mountain, so the number of paths will be contrary to the reality of distance, and the map is not accurate enough to be used. The comprehensive application of these six principles has correctly solved the problems of map scale, orientation, distance and their transformation. Therefore, six-body cartography became the basis of China's cartography theory before the Ming Dynasty, and occupied an important position in the history of cartography in China and the world.

Ji Li Fang Hua

"Drawing by map" is a method of drawing a map in proportion. When drawing, the map is first covered with squares, and the length of each side in the square represents the field, which is equivalent to the squares on the modern topographic map; Then draw the map content according to the grid to ensure a certain accuracy. According to written records, this method began with the principle of "six-body painting" put forward by Pei Xiu in Jin Dynasty. He once compiled a topographic abbot map with a scale of one inch and a hundred miles. In the Tang Dynasty, Jia Dan compiled a map of foreigners in the sea at a speed of 100 miles per inch. In the Northern Song Dynasty, Shen Kuo compiled a map of counties and counties in the world (also known as the map of guarding tombs). In the Yuan Dynasty, Zhu Siben drew a national map-map by a planned method, and its accuracy exceeded that of predecessors. This method has been used for 1500 years until the early Qing Dynasty, which is of great significance in the history of cartography in China and the world.

The Contribution of Monks in Tang Dynasty to Surveying and Mapping Science

Ancient astronomy in China has developed greatly since the Han Dynasty, and reached a new stage in the middle Tang Dynasty, in which a group of eminent monks made outstanding contributions.

In the Tang Dynasty, there were a group of eminent monks, formerly known as Zhang Sui, who were famous astronomers and surveyors. Wu Sansi, the descendant of Wu Zetian, tried his best to win over the imperial power, but Zhang was unwilling to be his accomplice, participated in state affairs, shaved his hair and became a monk. After the political turmoil after Wu Zetian, Emperor Xuanzong of the Tang Dynasty made great efforts to govern and created the rule of Kaiyuan. At that time, the astronomical calendar "Linde Calendar" had been used for 50 or 60 years. Because precession was not taken into account, it was not allowed to predict several eclipses, so Emperor Xuanzong of the Tang Dynasty recalled a monk who had been a monk for many years and put him in charge of changing the calendar.

After accepting the task, the parties asked Tai Shigong to "measure the size of the stars". However, the instruments preserved by Taishijian can no longer meet the needs of double calendars. Liang Lingzan, an official soldier who led Cao to join the army at that time, designed a device of the zodiac and made a wooden model of the device. With the support and leadership of our team, this musical instrument was cast with copper in the 11th year of Kaiyuan (AD 723). This instrument can be used to determine the position of the sun in the sky every day, as well as the positions of the moon and stars. In the same year, the delegation, Liang Lingzan and others designed and manufactured the "Waterborne Celestial Instrument" on the basis of Zhang Heng's "Waterborne Elephant" theory. The water-borne armillary sphere is engraved with 28 nights, and water is injected into the wheel once a day, which is exactly the same as the apparent motion of the celestial body on Sunday. Half of the water-borne armillary sphere is in the water tank, and the upper frame of the water tank is like the horizon. "Standing two meters above the horizon, the front drum is engraved for the morning, and the drum plays naturally all the time, and the clock rings naturally all the time." The whole water-borne armillary sphere can not only demonstrate the apparent motion of the sun, moon and stars, but also automatically tell the time. A group of people have achieved more than Zhang Heng.

According to the need of revising the old calendar, in 724 AD, the delegation organized and led the first astronomical geodetic survey in ancient China, which was also an unprecedented and rare nationwide astronomical geodetic survey. Under the unified command of the party, led by Taishi Jiannangong, they marched all over the country. The delegation is located in Chang 'an, the capital of China, to direct this great project.

The scope of this survey is very wide, with Henan Plain as the center, Ulaanbaatar in Mongolia in the north and Changde in Hunan in the south. In these places, they measured the length of the sun shadow and the height of the North Pole in winter solstice and summer solstice respectively, and drew the measurement results. The meridian length measured by them is the first time in the world, which is of great significance in the history of world science. In addition to providing reliable data for revising the calendar, this survey is more important to find out the difference between the shadow of the sun and the height difference of the North Pole on the earth at the same time. The measured data denied the wrong conclusion of the ancients that "the shadow of the sun is one inch, and the earth is thousands of miles away", and provided quite accurate values of the arc length of the meridian of the earth, which made great contributions to the correct understanding of the earth and created a way for people to understand the shape and size of the earth through actual measurement. This is a brilliant achievement in the history of world surveying and mapping.

What are the characteristics of Chinese and foreign people in the sea painted by Jia Dan?

Jia Dan was a geographer and cartographer in the Tang Dynasty. Throughout his life, he used Pei Xiu's cartography method to write four books: Daozhi of Ancient and Modern Counties, Nanzhi of Gulongshan, Ten Records of Zhenyuan, Four Records of China and Records of Tubo Yellow River.

At the age of 55, he organized painters to draw a map of China people and foreigners at sea, and it took 17 years to complete this huge map of China in the Tang Dynasty. This is another great map work of China after Pei Xiu, which is of great significance in the history of cartography in China and even in the world. This picture is a contrast between ancient and modern times, drawn in two colors. It has two characteristics: first, it pays attention to foreign parts, although it is an interview material, it pays attention to reality and corrects many mistakes; Second, it pays attention to the textual research of historical geography, and the ancient and modern place names are colored differently, creating a precedent for the evolution map of China. The width of the map of foreigners in the sea is about 10 square abbot, which is 10 times larger than Pei Xiu's map of topographic abbot, which shows the vastness of the project and the scale of drawing in the Tang Dynasty.

Shen Kuo's Achievements in Map Surveying and Mapping in Song Dynasty

Speaking of Shen Kuo, most people know that he wrote the immortal book Meng Qian Bi Tan. This work involves the observation of theories and phenomena in astronomy, calendar, geography, mathematics, physics, chemistry, biology, literature, history, music and art.

It is a rare encyclopedia in ancient China. Shen Kuo, a master of Neo-Confucianism, also made an indelible contribution to map surveying and mapping.

Shen Kuo likes studying since he was a child. He has traveled all over the world. He is interested in geography. His main contribution to map surveying and mapping is to make map models and draw up maps of various states and counties in the world. About the map model, Shen Kuo recorded it in detail in Meng Qian's Bi Tan. When he visited the frontier, it was not ideal to make a map model of the mountains and rivers he saw with sawdust, batter and melted wax, and then he carved a map model out of wood and presented it to the emperor. Because of its intuitive and realistic image, it was deeply appreciated by the monarch and ministers and highly respected by the court. This is probably the creation of the record map model in the history of cartography in China.

In A.D. 1076, Shen Kuo was ordered to edit the administrative division map of the whole country at that time, also known as Shouling Map. The map only includes the power scope of the Northern Song Dynasty, including guards, envoys and other officials. In the process of map compilation, Shen Kuo consulted the geographical data and maps since the Han Dynasty, checked the facts, eliminated the false and retained the true, and combined with his own personal experience, which lasted 12 years. In the meantime, Shen Kuo was politically suppressed, but after he went to the embassy and was demoted, he still didn't give up the job. There is a big map in this map that can be regarded as a national general map, and other road maps are divided into 18 according to the administrative division system at that time, all of which are beautifully framed with yellow silk.

Guo Shoujing's Surveying and Mapping Achievements in Yuan Dynasty

123 1 year, a boy was born in Xingtai, xing zhou (now Xingtai County, Hebei Province). When the boy was four or five years old, he was brilliant, liked reading and was particularly interested in exploring natural phenomena. In his early years, he made some small astronomical instruments. This boy is Guo Shoujing, one of the outstanding scientists in the world in the 3rd century.

At the age of 29, Guo Shoujing was ordered to visit Daming, Zhangde and other places. He was conscientious and down-to-earth, and especially made a detailed survey of the topography and water conservancy conditions where he went. Two years later. In the upper part (near Duolun, Inner Mongolia), he put forward six concrete suggestions on building water conservancy projects for Kublai Khan in Yuan Shizu. Kublai Khan appreciated this and ordered Guo Shoujing to lift all the canals. Later, the official went to the Ministry of Industry as a doctor and has been in charge of river engineering and water conservancy. During this period, there were hundreds of rivers, canals, berths and dams surveyed in Guo Shoujing, among which the topographic survey in the middle reaches of the Yellow River and the leveling survey along the Beijing-Bian River made creative achievements.

Guo Shoujing's greatest contribution to surveying and mapping is that he took the sea level along the coast of China as the datum of leveling. At that time, Guo Shoujing had set out from Mengmen Mountain (now Yichuan, Shaanxi Province to Jixian, Shanxi Province) to the east along Zhongtiao Mountain, surveyed the terrain along the old course of the Yellow River, and mastered the terrain changes in hundreds of miles north of the Yellow River. This is a large-scale topographic survey in the middle reaches of the Yellow River. The unification and standardization of local measurement data must be solved in large-area measurement. According to "A Brief Introduction to Famous Officials in Yuan Dynasty", Guo Shoujing "tasted the difference between the sea level and the terrain of Gyeonggi, saying that the water of Gyeonggi is far from the sea, and its flow is steep, while the water of Gyeonggi is offshore, its flow is slow, and its word size is small. There is no such thing as water conservancy. " This is the first time in the history books of China that a unified altitude system is established based on sea level, and the scientific concept of "altitude" is founded. This work is of great significance to the development of surveying and is an outstanding scientific achievement bred by the development of large-scale surveying in China. Up to now, the leveling results of regional survey in all countries in the world are based on the average sea level at a certain point along the coast and are naturalized in the height system. In China, the average sea level of the Yellow Sea recorded by the tidal station of Qingdao Port over the years is taken as the benchmark, and the leveling origin is set in Qingdao as the benchmark of national elevation. This scientific method. Will continue to be used.

What kind of instruments are armillary sphere and Jane instrument?

When you visit Nanjing Purple Mountain Observatory, people will see two strange ancient instruments. Among them, the ring with complex structure is called armillary sphere; The two groups of columns supporting the double ring are called Jane instruments. They were made in the Ming Dynasty and are a valuable cultural heritage of our country.

The armillary sphere is about 2.75 meters high, 2.48 meters long and 2.46 meters wide. Jane is about 2.5 meters high, 4.4 meters long and 2.9 meters wide. They are all made of bronze, with strong structure and gorgeous craftsmanship. It is very high at close range and exquisite at a distance. They are the crystallization of the highly developed ancient science and technology, smelting and casting techniques and machinery manufacturing in China. They are really exquisite astronomical instruments and rare artistic treasures.

In ancient China, the armillary sphere was used to measure the coordinates of celestial spheres. It existed in the Warring States period, but it was not necessarily called the armillary sphere. The armillary sphere is complex in structure and consists of concentric rings, like a hollow sphere. These circles represent the horizon circle, meridian circle circle, equatorial circle, right ascension circle, ecliptic circle and white circle respectively. Zhang Heng, an astronomer in the Eastern Han Dynasty, said, "If you set a circle, it will be muddy", so he called this instrument the armillary sphere.

The armillary sphere has been continuously improved in the application process, but the general idea is to increase the number of rings, which makes the structure more complicated, increases the range of shielding the starry sky and affects the observation. In addition, it is very difficult to install multiple rings concentrically, which leads to poor eccentricity of the armillary sphere. Shen Kuo, a scientist in the Northern Song Dynasty, first canceled the white ring on the armillary sphere and opened up a new way to simplify the armillary sphere. In the Yuan Dynasty, Guo Shoujing, Wang Xun and other scientists improved the armillary sphere on a large scale on the basis of Shen Kuo, created new simple instruments and further abolished the ecliptic ring. In this way, the simple instrument is separated from the complex structure of the armillary sphere and decomposed into two independent instruments: the equatorial theodolite composed of equatorial ring and right ascension ring and the horizon theodolite composed of horizon ring and horizon meridian ring. This simple instrument has a very simple structure, which greatly increases the observation field of vision, overcomes the two biggest defects of the armillary sphere and greatly improves the observation accuracy. Equatorial theodolite and horizon theodolite are packaged on the same rectangular copper base, which is always called simple instrument.

During observation, the stars in any position on the celestial sphere can be observed by rotating the right ascension double-ring and peephole of the right ascension instrument, and the depolarization of the celestial body can be read from the right ascension double-ring scale. As for the right ascension value of celestial bodies, it can be obtained on the equatorial ring at the southern end of the rotation. Jane's horizon theodolite is actually a new creation. During observation, the azimuth and altitude angle of any celestial body can be measured by rotating the vertical double ring and the peeping tube.

In the change of time, the armillary sphere and simple instruments have weathered. 1900, when Eight-Nation Alliance invaded Beijing, the French army snatched Jane from the French embassy, and it took several years to return her. The Germans took the armillary sphere in Potsdam, Germany, and it was not until 192 1 that it was returned to China. After the September 18th Incident, Hunyi and Jianyi moved to Nanjing Purple Mountain. After the Japanese occupation of Nanjing, they wantonly destroyed instruments. After the founding of New China, these instruments were well protected.