Chapter 18 Section 6 Shen Kuo’s Cartographic Achievements

Shen Kuo (AD 1031-1095) was one of the most outstanding scientists in Chinese history, as well as an outstanding geographer and cartographer. In the Song Dynasty, instruments such as "level" (level), "wangchi" (photo board), and "ganchi" (dugan) were widely used to measure the height of the terrain.According to the "Wu Jing Zong Yao", the shape of this level is similar to a plate or theodolite, and it is a water tank with three buoys, and each buoy has an observation point.Shen Kuo believed that there was a certain error in measuring with this instrument, so when he was ordered to measure the terrain of Bianqu in the fifth year of Xining (1072 A.D.), he used the old ditch left after the soil was borrowed outside the dike of Bianqu to divide the ditch into three parts. For several sections, water is blocked and weirs are built, and the height difference between each section is calculated by using the water level, and then the total height difference is obtained.Shen Kuo measured that the elevation difference between Shangshanmen in Kaifeng and Huaikou in Sizhou was 19.486 feet.His measurement method has never been precedent in the world before, and it belongs to his initiative.

In the seventh year of Xining (AD 1074), Shen Kuo was ordered to patrol the northern frontier.In order to show the real situation of the mountains and roads more vividly, a three-dimensional "wooden map" was made during this period.He first made a detailed on-the-spot survey of the mountains and rivers within the scope of the map, and then used batter to coat wood chips to restore the topography on the wooden plate.But soon the weather turned cold, and the sawdust froze and could no longer be used. Considering that the wax was light and easy to carry, he melted the wax to make a model.After returning to the capital, he used wood to carve a three-dimensional map based on the shape of wax.Song Shenzong summoned ministers to watch it together. He thought it was worth promoting, and ordered all frontier states to make such "wooden pictures" and submit them to the imperial court for collection.Shen Kuo's three-dimensional map was produced more than 700 years earlier than Western Europe, but it seems that it has not been popularized and circulated since then, obviously because of the difficulty of making it, because it is difficult for ordinary people to have two conditions at the same time - to be able to conduct on-the-spot observations and to be able to Master the scale in production.In the Southern Song Dynasty, Huang Chang made a wooden map; Zhu Xi tried to make it with clay, and later tried to use eight wooden boards to make a combined "Hua Yi Map", and carved the shape and height of mountains and rivers on the wooden boards, but failed. .

In August of the ninth year of Xining (AD 1076), Shen Kuo was ordered to compile and draw "Tianxia Zhouxian Tu" during his tenure as the third division envoy.Although he suffered several setbacks in his official career and was once demoted to exile, he never gave up his efforts and finally compiled it in the second year of Yuanyou (AD 1087), officially named it "Shouling Tu", and reported it to the court the next year.This set of maps includes "big map and one axis" (a national general map), 1.2 feet high, 1 foot wide, and a scale of about 1:400,000; a small scale national general map, whose size is unknown; 18 roads ( There is one sub-map for each of the first-level administrative regions at that time; a set of copies has a total of 20 pictures; a total of 40 axes (pictures).This set of maps still existed in the Southern Song Dynasty, because it was listed as "remembered" (existing) when Zheng Qiao compiled "Tongzhi Tupulue", and it was lost after that.Some people believe that, based on the time and place when Shen Kuo drew the "Shouling Tu" and the situation that he settled in Zhenjiang after completing the compilation, as well as the seven years of Fuchang (1136 A.D. Forest of Steles) and Shaoxing 12th Year of Zhenjiang Fu Xue Lishi "Yuji Tu" (existing Zhenjiang City) and other facts, the "Yuji Tu" on Qixue Shangshi may be the one in Shen Kuo's "Shouling Tu" That little picture.

When summarizing the experience of drawing the "Picture of Keeping Orders", Shen Kuo pointed out: In the book of geography, the ancients had pictures of flying birds, but I don't know who made them.The so-called flying birds mean that although there are four arrivals, the number of miles is all along the road.The road is straight and irregular, and since it is listed as a map, there is no correspondence between the miles and the steps. Therefore, according to the map, it is straight and straight, like a bird flying in the sky, and there is no difference between mountains and rivers.I tasted the map of keeping orders, although the ratio is divided by two inches and hundreds of miles, and the seven methods of looking up and looking at the teeth and judging from the side, sideways, oblique, and straight, are used to get the number of birds flying.Once the picture is completed, this method can be applied only when the reality of the distance and distance of the corner is obtained.Divided into four to, eight to, for twenty-four to.It is named after the four hexagrams of Twelve Branches, A, B, B, D, G, Xin, Ren, Gui, Ba Gan, Qian Kun, Gen Xun.Even though the pictures of later generations are dead, they can be given this book. According to the twenty-fourth to Yibu County, the pictures can be completed immediately, without any mistakes. ("Mengxi Bi Tan Continuation" Volume 3)

Based on this, he believes that the essence of the so-called "flying bird map" by the ancients is to obtain the straight-line distance between two points on the ground just like a bird in the sky flying in a straight line, so as to ensure the accuracy of the map.Compared with Pei Xiu's "Six Body of Mapping", Shen Kuo canceled "Dao Li" and added "Mutual Tong".Shen Kuo regarded "Daoli" as the distance on the map, thinking that with the scale, the distance on the map would naturally exist.As for his newly proposed "mutual identity", it is likely to be the contour line mark used in modern map surveying and mapping.When noting the directions of prefectures and counties, Shen Kuo expanded the 8 directions used by predecessors to 24, making the positions and interrelationships of each location more precise.