He was a student of Thales, the founder of ancient Greek science. Like his teacher, he introduced ancient oriental science to Greece. For example, he was the first Greek to use the sundial, and China in the East, Babylonian in Central Asia, and Egyptians knew it hundreds of years ago. Although maps (local maps) appeared in the Western Zhou Dynasty in China, anaximander was the first person to draw a global map according to his own understanding of the earth. His most important contribution to science is astronomy. He realized that celestial bodies revolve around Polaris, so he painted the sky as a complete sphere, not just a hemispherical arch above the earth. Since then, the concept of sphere has entered the field of astronomy for the first time, which eventually led to Ptolemy's complex (but wrong) map of the universe. So some people think that he is the founder of astronomy. He also realized that the surface of the earth must be curved, because when you travel, the positions of the planets will change. He thought that the north-south curvature was obvious enough, so he painted the earth as a cylinder with an east-west axis, and the height was one-third of the radius. As for the concept that the earth is a ball, Pythagoras and his students put it forward decades later. There is only one proposition left in anaximander's works. Therefore, some authors' reports later became the main record of his findings. That proposition compares the rise and fall of this special substance, water or fire, to the retribution of good and evil in human society. For example, whether it is cold or hot, it will never be better than the other side, but each side will "pay compensation" to maintain the balance between the two. He believes that the world is made up of an imperceptible substance called infinity. This imperceptible material stage is before it is separated into cold, hot, wet and so on, so it embodies the initial unity of all phenomena. Anaximander's statement is obviously just speculation and imagination, but it is a simple materialistic view of the universe, which attempts to explain the origin and conditions of the universe with matter itself for the first time. This primitive theory of evolution is contrary to traditional religion.
2 Pei Xiu's Map of Gong Yu in the Western Jin Dynasty.
Pei Xiu's Eighteen Prefaces of Yugong Area Map expounds his scientific mapping method.
Six-body painting. This is the six principles of mapping that he creatively put forward. The so-called "six bodies",
One is "fraction", that is, scale; The second is "quasi-hope", that is, orientation; The third is "truth", that is, the reality of Tao.
International routes and their distances; The fourth is "competition", that is, the ups and downs of the terrain; The fifth is "evil", which means Tao.
Such as a temporary hook, evil means that Tao is like the string of a bow, and the distance is different; Sixth, it means "winding and straight", which means the road is winding and straight.
The road is straight and the distance is different. Pei Xiu's Painting Six Bodies, the first three are the main principles of painting, and the last three.
Because the terrain is undulating, it is a problem that draftsmen should consider. These six principles complement each other,
It laid a scientific foundation for the compilation of maps and had a great influence on the development of cartography in later generations. from
After Pei Xiu, until the end of Ming Dynasty, the map drawing method of China was basically carried out according to Pei Xiu's "six-body".
This is the main problem of cartography research today. In addition to latitude and longitude and projection, it is in cartography VI.
Body "has been mentioned.
Pei Xiu's other great contribution to cartography is to restore the world map to the abbot map.
He felt that the original "big picture of the world" made of eighty horses was too inconvenient to use, so he divided it into ten horses.
Li, one inch is a hundred miles ",and the" World Map "was compiled into the" Abbot Map ". This "Abbot"
The map records the geographical elements such as mountains, cities and villages in detail, which is very convenient to carry and read.
The abbot map has been circulated for hundreds of years. Ou Yangxun's Bei Tang Shu Chao and Zhang Yanyuan's Records of Famous Paintings of Past Dynasties in the Tang Dynasty.
Both mentioned Pei Xiu's abbot diagram.
Pei Xiu lived in the Western Jin Dynasty for the second half of his life, and his customs were immoral. Scholars learn from Laozi and Zhuangzi and talk about nothingness.
Be a man, walk cautiously with animals, be talented as an official, and sign a contract with a noble person as usual. Pei Xiu
In this environment, I have a strong dedication to science and the spirit of hard study, and finally get ahead.
It is very commendable to have made outstanding achievements in science.
Pei Xiu died in the seventh year of Taishi in the Western Jin Dynasty (>>
Question 2: There were no artificial satellites in ancient times. How did the ancients draw accurate maps of the world? Historical records. The next century: the left is the right, and the four seasons are established, so as to open Kyushu, connect Jiulu, deny Jiuhe and swim Jiusan.
Of course, as we all know, there is no exact theory about Xia in historical records, and Tai Shigong often digs such unreliable pits.
But the precision, rope, rules and moments mentioned in this sentence are the four tools used to measure the map.
Specific documents proving that China people have map records can be found in a large number of records during the Warring States period.
"Zhou Li. Situ, a local official: the post of big Situ, in charge of the national map and its number, to help Wang An disturb the country. Based on the land map of the world, it is well known that Kyushu has a vast territory with clear mountains, hills and graves.
Since Zhou Zhou, I have had a certain understanding of the importance of maps, and regarded it as an important duty of the master plan.
Specific to the method of drawing a map, we must first talk about a person, and this person is called Pei Xiu.
Pei Xiu was active in the Zen realm of Wei and Jin Dynasties, a native of Hedong and the son of Pei Qian. Almost everyone who has seen the reflection knows him.
This guy is a wayward teenager. He loved freedom all his life. He really loved freedom. ...
Later, Jia Chong and Xun became active as the troika of Sima family. The most important thing they did was to welcome Cao Huan after the death of Cao Pi.
Pei Xiu was a keyboard player when he was a teenager, and he liked to express his views on current affairs. When there are guests at home, he will listen to Pei Xiu's remarks to see his father's face.
Later, Pei Xiu, who knew nothing about mechanical design, went to spray the catapult designed by Ma Jun. Ma Jun was not good at arguing and ignored him.
This guy is arrogant and likes to express his opinions. He is a conceited sprayer. One of the main reasons is that Ya has a high IQ. ...
In the fourth year of Taishi, Pei Xiuren was commonplace in the Western Jin Dynasty. In the seventh year of Taishi, Pei Xiu took a high bag of Wushi powder and drank cold wine, then committed suicide.
In just three years, Pei Xiu became one of the most important cartographic experts and geographers in the history of China. ...
Why do you think it only took him three years? Because Pei Xiu's previous work has nothing to do with painting.
When he worked as a small staff officer in Si Mazhao for several years, he probably came into contact with cartography, and most of the time he was in Si Mazhao to help hurt people.
Let's not talk about Pei Xiu's merits and contributions. Let's introduce the tools used by ancient people in China to draw maps.
From ancient literature, we can determine the tools for drawing maps as follows:
Rules, times, standards, ropes and watches; Pillar, compass, observation tube, measuring rod; Remember to drum up the car and measure the pedestrians.
Basically, it is the eleventh middle school, in which the compass, observation tube and watch are used to measure the direction, and the other eight functions are different.
The compass was invented in the Northern Song Dynasty, but it was useless in Pei Xiu's time. They used the primitive SiNa and territory.
What is the site? It is a slate with four dimensions, eight stems, twelve branches and twenty-four directions.
Then there is a spoon-shaped magnet called Sina, put it on it and suck it. Turn and stop in the south direction.
Sounds familiar, right? You must have seen it on science and education programs. This thing has too much friction and too much error, so the compass was replaced after it appeared.
Question 3: How did ancient people draw maps? What tools do you use? How are the steps? The development of ancient maps ―― The development history of ancient maps has different characteristics in the East and the West. According to records, the Yellow Emperor of China used a map to fight against Chiyou. During the Xia and Yu dynasties, Dayu cast a map of Jiuding. There are records such as "World Map" and "Land Map" in Zhou Li of Zhou Dynasty, indicating that maps were already used for production and land management at that time. Since the emergence of agriculture in the Yellow River basin, the middle and lower reaches of the Yellow River have been the cradle of ancient oriental culture. It can be said that the development of China map is due to the needs of agricultural life and war. During the Spring and Autumn Period, a new mathematical calculation method appeared due to the needs of farmland water conservancy and military engineering. Although the map at that time has not been handed down, it is not difficult to imagine that the map has been widely used. For example, when Confucius saw people engaged in land survey and household registration statistics, he greeted them in the car to show his respect; In order to assassinate the king of Qin, Jing Ke asked for an audience in the name of offering a picture. This shows that the map at that time was an important tool in the hands of rulers. According to records, there were land maps, administrative maps, military traffic maps, world general trend maps, maps of mines and tombs in ancient China. The earliest ancient maps of China that can be seen now are three maps unearthed from Mawangdui Han Tomb in Changsha in BC 1973, which were buried in BC 168, namely topographic map, garrison map and city map. The scope of the map is similar to that of Hunan, Guangdong and Guangxi provinces, and the content and representation are roughly the same as those of modern maps. These maps enjoy a high reputation in the history of map development. With the development of western maps, it is more certain that when agriculture began to exist along the Nile in ancient Egypt, the river flooded the farmland in spring and washed away the boundaries of the fields. In order to redefine the land, a map with mathematical significance has been produced, which graphically represents the land corridor and quantity. In ancient Greece and Rome, due to the development of handicrafts, the development of maps shifted from agriculture to maritime trade and military war. They learned the knowledge of geometry and geography in Egypt, and compiled large-scale, accurate charts and large-scale and small-scale world maps. In the history of ancient map science, there are two world-recognized cartographers. One is Ptolemy of Greece (AD 90- 168), who studied how to draw the spherical surface of the earth on a plane, and put forward two drawing methods of the world map, one is to draw the longitude and latitude lines into a simple sector, and the other is to draw a spherical surface. This method is called map projection. This is a very important foundation and one of the most important contributions of the early west to cartography. Ptolemy discussed the method of determining the shape, size and latitude and longitude of the earth in his book "Geographic Guide", and chose the meridian crossing Ferro Island in the Atlantic Ocean. This method has been used until 1884. He was the first person to draw a map of the world with ordinary conic projection. His works are of epoch-making significance in the history of ancient western maps, and he is called the founder of map science. The other is Pei Xiu (AD 224-27 1) in the Western Jin Dynasty in China, who compiled A General Survey of Yugong Region and Topographic Abbot Map. The former is a historical map, while the latter is a simplified map of the State of Jin. He put forward the "six bodies of cartography", that is, the principles of scale, orientation and distance in map drawing, which laid the theoretical foundation of ancient cartography in China. The planning method he adopted had a long-term impact on the pattern of ancient China map drawing, and was highly praised by famous geographers in later generations. To sum up, China's ancient map-making is not inferior to that of the West in practice or theory, and it has unique ideas in the West, so it should be sorted out, instead of belittling itself and humiliating foreigners. Zheng He was a famous navigator in Ming Dynasty. He was born in 137 1. Real name horse, fine print. /kloc-at the age of 0/2, he was taken into the palace and served as a waiter for Prince Judy. When he became emperor, he was promoted to the eunuch of the Inner Palace, surnamed Zheng, also known as the "Sambo eunuch". In order to consolidate her dominant position and expand her political influence, Judy resumed the maritime traffic interrupted by the Yuan Dynasty. Zheng He was well-versed in * * * language, and was highly valued by Judy. He was sent to lead the fleet to the Western Seas for seven times. At that time, the so-called western ocean refers to the vast area west of the South China Sea, including the Indian Ocean and coastal areas. Zheng He commanded about 20,000 sailors, soldiers, medical officers, comprador, etc. Many times, and took away more than 100 treasure ships, which were much larger than the three ships with insufficient load 100 tons discovered by Columbus in the New World of America. From 1405 to 1433, seven voyages took 28 years and passed through 37 countries. Zheng He was the first China native to cross the Indian Ocean to reach the east coast of Africa, before Columbus 1492 crossed the Atlantic to reach America and Portuguese da Gama 147 1 year bypassed the Cape of Good Hope to reach the Indian Ocean on the south coast of Africa ...
Question 4: How were ancient maps drawn? The map was drawn in ancient China. The following are several representative evolutionary histories from the Three Kingdoms period to the Yuan Dynasty. From the narration, we can know how the ancients measured and drew maps.
China also had the ability to draw nautical charts in the Song Dynasty. Of course, science developed rapidly after the Yuan Dynasty (for example, the hybrid seismograph can measure astronomy). At the same time, the development of foreign science is also wonderful ... (for example, the map of Taiwan Province Province drawn by the Dutch sailing around Taiwan Province Province).
The first monograph on calculation ―― Classic of island calculation
The Book of Island Calculations was written by Liu Hui, a mathematician in the Three Kingdoms Period (3rd century BC). 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 islands (lookout island), measuring the height of pine trees on mountains (lookout pine), measuring the size of cities (lookout city), measuring the depth of gullies (lookout valley), measuring the height of towers above 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 mountains)
In order to solve these problems, Liu Hui put forward specific calculation methods, such as repeated table method, continuous cable method, cumulative distance method and so on. 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.
What is n "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 born in Wenxi, Hedong (now Shanxi). When Emperor Wu of Jin lost the lawsuit, he became prime minister. He looked up the old map 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 the roads were straight".
Because of the rough drawing of the old map and the change of place names, he compiled the earliest atlas of China-Gong Yu regional map and topographic local map with the help of the scene. 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 "Road Y", which is used to determine the road distance between the two places; The fourth is "competition", that is, relative elevation; The fifth is "square evil", that is, the fluctuation of ground slope; The sixth is "straightness", 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 the prospect, then the map accuracy of n here is ok, and there will be deviations in other places; With orientation and no road y, 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.
projecty rts 3d
"Y Plan" is a method of drawing maps in proportion. When drawing, the map is first covered with squares, and the length of each side in the square represents the field Y number, which is equivalent to the square Y grid 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 diagram" 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.
Tang dynasty >>
Question 5: How was the ancient map drawn? According to records, the Yellow Emperor of China used a map to fight against Chiyou.
During the Xia and Yu dynasties, Dayu cast a map of Jiuding.
There are records such as "World Map" and "Land Map" in Zhou Li of Zhou Dynasty, indicating that maps were already used for production and land management at that time. Since the emergence of agriculture in the Yellow River basin, the middle and lower reaches of the Yellow River have been the cradle of ancient oriental culture. It can be said that the development of China map is due to the needs of agricultural life and war.
During the Spring and Autumn Period, a new mathematical calculation method appeared due to the needs of farmland water conservancy and military engineering. Although the map at that time has not been handed down, it is not difficult to imagine that the map has been widely used. For example, when Confucius saw people engaged in land survey and household registration statistics, he greeted them in the car to show his respect; In order to assassinate the king of Qin, Jing Ke asked for an audience in the name of offering a picture. This shows that the map at that time was an important tool in the hands of rulers. According to records, there were land maps, administrative maps, military traffic maps, world general trend maps, maps of mines and tombs in ancient China. The earliest ancient maps of China that can be seen now are three maps unearthed from Mawangdui Han Tomb in Changsha in BC 1973, which were buried in BC 168, namely topographic map, garrison map and city map. The scope of the map is similar to that of Hunan, Guangdong and Guangxi provinces, and the content and representation are roughly the same as those of modern maps. These maps enjoy a high reputation in the history of map development.
In the history of ancient map science, there are two world-recognized cartographers. One is Ptolemy of Greece (AD 90- 168), who studied how to draw the spherical surface of the earth on a plane, and put forward two drawing methods of the world map, one is to draw the longitude and latitude lines into a simple sector, and the other is to draw a spherical surface. This method is called map projection. This is a very important foundation and one of the most important contributions of the early west to cartography. Ptolemy discussed the method of determining the shape, size and latitude and longitude of the earth in his book "Geographic Guide", and chose the meridian crossing Ferro Island in the Atlantic Ocean. This method has been used until 1884. He was the first person to draw a map of the world with ordinary conic projection. His works are of epoch-making significance in the history of ancient western maps, and he is called the founder of map science. The other is Pei Xiu of the Western Jin Dynasty in China (AD 224-27 1), who compiled A General Map of Yugong Region and A Map of Topography Abbot. The former is a historical map, while the latter is a simplified map of the State of Jin. He put forward the "six bodies of cartography", that is, the principles of scale, orientation and distance in map drawing, which laid the theoretical foundation of ancient cartography in China. The planning method he adopted had a long-term impact on the pattern of ancient China map drawing, and was highly praised by famous geographers in later generations.
Question 6: How was the world map drawn hundreds of years ago? If in ancient times,
The ancients were also very clever. Although they don't know professional mathematics knowledge such as latitude and longitude, plane rectangular coordinate system, they can use the same principle. First, determine a realistic unit length (this is determined according to your own map scale), then scale it according to a certain proportion, so that there will be a scaled unit length on the paper, and then make a field trip and draw the geomorphological features of the realistic unit length on the paper according to the same proportion. In this way, we can plan the map more accurately. However, the map made by this method can not express the height, but only explain the terrain.
Question 7: How to draw historical maps and ancient maps of China?
Island Calculation is a surveying work written by Liu Hui, a mathematician of Wei State in the Three Kingdoms period. It was originally the continuation and development of the Pythagoras chapter in the ninth volume of Liu Hui's Notes on Nine Chapters of Arithmetic. The book ***9 questions all use measurement to calculate height, depth and distance. The first problem is to calculate the height and distance of the island, hence the name. Island Calculations is the earliest mathematical work of surveying and mapping in China, which also provides a mathematical basis for cartography.
Pei Xiu (224-271) was born in Wenxi, Hedong (now wenxi county, Shanxi) in Wei and Jin Dynasties, and was a minister and scholar in the Western Jin Dynasty. In the Three Kingdoms period, Wei San rode as a constant servant, Shang Shu as a servant, Jin Guanglu as a doctor, Sikong and Feng Julu as county magistrates, and made a map of Gong Yu, which initiated the study of ancient map drawing in China.
Pei Xiu's greatest contribution to cartography is the six principles of cartography put forward in the preface of Gong Yu Area Map.
Draw six bodies:
One is the fraction, which reflects the ratio of area to length and width, that is, the current 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 the evil, that is, the slope of the ground fluctuates;
Sixth, circuitous, that is, the conversion between site ups and downs and the distance on the map.
Note: There are three different interpretations of "six styles": superior, superior, evil and pedantic. Generally speaking, according to the original text and considering the basic rules of cartography, it should be understood as three factors and methods to change the road length between two places (including errors caused by road undulation and bending) into a straight line length on the horizontal plane.
On this basis, Pei Xiu completed 18 regional maps of Gong Yu, which is the earliest historical atlas in China, and the "six painting methods" came from the preface of this book. It's a pity that this book has long been lost.
This "six-body painting" proposed by Pei Xiu was the most scientific and perfect painting theory in the world at that time. In addition to longitude and latitude and earth projection, he proposed almost all the main factors that should be considered in modern cartography.
Jia Dan (730 ~ 805) studied Pei Xiu's six methods and drew the world-famous "Hai Hua Yi Tu". Jia Dan was a geographer and cartographer in the Tang Dynasty. He adopted Pei Xiu's drawing method and organized a painter at the age of 55. It took 17 years to draw a huge map of China in the Tang Dynasty. 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 scale of cartography in Tang Dynasty.
Yi Tu of Haihua is another China map masterpiece after Pei Xiu, which is of great significance in the map history of China and the world. Its main feature is that it pays attention to the textual research of historical geography, and the ancient and modern place names are marked with different colors, creating a precedent for the evolution map of China.
Song Dynasty is a glorious era in the map history of our country. Shortly after the reunification of the Northern Song Dynasty, the national master map "Chunhua Tianxia Map" was compiled based on more than 400 maps donated from all over the country. In today's forest of steles, there is a stone carved in Shaoxing for seven years in the Southern Song Dynasty, with flowers and pictures on both sides. The picture on the right is a part of the planned Yuji map in the planning map. As can be seen from the graphics of the Yangtze River and the Yellow River, the accuracy of the pictures is very high. In the Song Dynasty, Shen Kuo (A.D. 103 1 ~ 1095) conducted a large-scale leveling, found the existence of magnetic declination, and revised the compass to 24 directions. The map of Shouling compiled by him is an atlas of states and counties in the world, including 20 maps. He is also the author of the scientific book On Meng Xi.
Question 8: In ancient times without high technology, how did people use primitive geodetic tools to draw maps? The principle is the same as modern measuring instruments. At the latest, when Lingqu and Dujiangyan were built during the Warring States period, the horizontal height was measured with horizontal measuring columns and rotatable columns, which is the predecessor of the current horizontal measuring instruments. The calculation method should be trigonometric geometry (approximate pythagorean theorem and its extension), which can be found in jules verne's The Devil in South Boisne. These modern measuring instruments seem to be advanced, in fact, the principle is determined in the elements of geometry in ancient Greece.
Question 9: How were the maps of the ancients drawn? The story of Dayu's water control is well known. According to "Historical Records", he was "left-handed and right-handed", with surveying and mapping tools in his hand, "walking mountains and rivers, setting mountains and rivers". According to legend, Hebo, the god of the Yellow River, once gave Dayu a slate engraved with a map of the Yellow River basin. These are the reflections of the map surveying and mapping at that time. After the flood control, Dayu traveled around the world, designated China's land as Kyushu, and inspected local products and land to determine tributes, thus forming the pre-Qin geographical masterpiece Yu Gong. Since then, "Kyushu" has become synonymous with the land of China, and "Gong Yu" has become a proper term for geographical works.
To draw a map, you must first measure it. The ancients developed many methods from simple to complex.
According to the Spring and Autumn Wei, Emperor Yan, one of the five emperors, traveled hundreds of thousands of miles to measure the earth. Dayu also sent Qiu Zhang to survey the whole territory of Shu Hai from east to west and from north to south. It can be seen that survey was one of the basic methods of geodesy at that time, so that thousands of years later, some people named the map "Yu Trace Map", which means the footprint of Dayu.
According to Liu Xin's Miscellanies of Xijing in the Western Han Dynasty, there is a kind of rail car that can calculate mileage, which was improved by Zhang Heng in the Eastern Han Dynasty. This kind of car adopts the principle of differential gear, which rings the drum once every ten miles and the bell once every ten miles, which greatly improves the speed of mileage measurement.
Vertical rod shadow measurement is a method to estimate the distance and position by measuring the length of sun shadow. The specific method is as follows: at noon that day, the watch poles with the same height (generally 8 feet high, equivalent to 1.88 meters) were erected in the north and south directions, and then the shadow of the watch poles was measured. According to "an inch of shadow is a thousand miles away" (the shadow of the sun is an inch, and the distance between the north and the south is calculated. According to Zhou Li, the shadow length from summer to the sun is/kloc-0.
"One inch of a thousand miles" is a rather rough empirical value, which was later denied by the theories and measurements of the southern astronomer He Chengtian, the Sui astronomer Liu Zhuo, the Tang astronomer monk and his entourage, and the Nangong theory.
As early as the Western Han Dynasty, Huainanzi recorded the basic method of measuring the height of the sun. When he arrived in the Three Kingdoms, Zhao Shuang, a native of the State of Wu, drew a map of the sun's height while taking notes on Zhou pian Shu Jing. The sun height map is a schematic diagram for calculating the sun height by measuring the sun shadow at two poles. Using the principle of similar triangles's side length ratio to measure the height of the sun and the long distance between the two places, it provides a method for indirect measurement. Mathematician Liu Hui said: "Anyone who looks extremely high and measures extremely deeply and knows its distance at the same time must use heavy difference." There are nine examples in his book gravity difference, including measuring the heights of islands, pine trees and buildings, measuring the size of cities, measuring the depth of valleys, and measuring the widths of estuaries and lakes.
After the Han Dynasty, the surveying tools such as armillary sphere, moment-covering and star-pulling board were invented one after another, which made the astronomical geodesic activities more active and the methods more precise. The methods commonly used in the pre-Qin period, such as stepping, surveying and vertical polar shadow surveying, still have vitality. During the Wanli period of the Ming Dynasty (1582), Matteo Ricci, an Italian missionary, came to China and brought western astronomical geodetic methods. In order to compile the calendar, in the second year of Chongzhen (1629), under the auspices of Xu Guangqi, assistant minister of the Ministry of Rites, the Western Bureau was established, which was attended by westerners coming to China and adopted western calculation methods, and carried out astronomical observations together with the Central Bureau which adopted China's traditional astronomical measurement methods. After five years of preparation, 10 kinds of new instruments, such as quadrant, astronomical clock, horizontal hanging armillary sphere, latitude and longitude celestial sphere, and timing telescope, have been manufactured, and practical observations with the contents of measuring time, azimuth, meridian and arctic height have been implemented. The trend of western methods replacing China and France has emerged. Western modern astronomical surveying and mapping methods were adopted in the national map surveying and mapping in the early and late Qing Dynasty.
Guyuan area map
Direction, Legend and Scale: How did the ancients draw maps?
The painted map of Guyuan House in the late Ming Dynasty is very strange. The whole map is radial, the painter stands in the center, and the map presents its scenes facing all directions. And it is different from the usual direction of going up north and down south. This picture is up east and down west, left north and right south. According to Su Pinhong, deputy director of the Ancient Books Museum of the National Library, it is easy to determine the direction according to the level of ancient science and technology, but the ancients often determined the direction according to actual needs when drawing maps, sometimes with labels and sometimes without labels.
Guang Yu Tu, edited by Mindeiro Hongxian, is evenly divided with a square grid, like modern longitude and latitude lines. According to reports, this is an auxiliary line for drawing maps on a scale in ancient times, which is called "the plan in the plan", and the length of the middle side of the square represents ... & gt