China has a vast territory and a long coastline. It is not only a continental country, but also a maritime country. Navigation has developed since ancient times.
Astronomical navigation technology
Astronomical navigation technology mainly refers to various methods of observing celestial bodies at sea to determine the position of ships. In ancient China, when we sailed to the sea, we knew for a long time to look at celestial bodies to determine our direction. Huainanzi in the Western Han Dynasty said that you can't know the east and the west by boat in the sea, and you will understand it when you see the North Star. ("Qi Customary Training": "A boat is confused, knowing everything, seeing the extreme and realizing it." Ge Hong's "Family Records of Bao Puzi" in Jin Dynasty also said that if you get lost in Yunmeng (an ancient place name), you must rely on a guide car to lead the way; Lost in the sea, you must look at the North Star to determine your direction. ("those who dream of clouds will know; Those who are offshore will be extremely arrogant. " Fa Xian of the Eastern Jin Dynasty said when he returned to China by boat from India that what he saw at that time was "vast and boundless, and he knew nothing but the sun, the moon and the stars." Until the Northern Song Dynasty, sailing was still "watching the stars at night and the sun during the day". It was not until the Northern Song Dynasty that the phrase "Look at the compass on a cloudy day" was added.
Around the Yuan and Ming Dynasties, China's astronomical navigation technology had made great progress, and it was already possible to determine the geographical latitude by observing the height of stars. This is the pioneer of ancient marine astronomy in China. This method was called "pulling stars" at that time. The tool for drawing stars is called the Star Sketchpad.
Star board is made of high quality ebony. A * * * Twelve square wooden boards, the largest one is about 24 cm long on each side, the lower one is decreasing by 2 cm, and the smallest one is about 2 cm long on each side. The other small square is made of ivory, and there are gaps in four corners. The lengths of the four cut edges are respectively one quarter, one half, three quarters and one eighth of the minimum edge length. For example, observe Polaris with a lead plate, hold the center of one end of the plate with your left hand, and look at the sky with your arms straight. The upper edge of the board is Polaris and the lower edge is horizontal, so you can measure the height of Polaris from the horizontal direction. Twelve wooden boards and four notched ivory blocks can be replaced and adjusted to different heights. After obtaining the height of Polaris, the geographical latitude of the location can be calculated.
In the Yuan Dynasty, the Italian Kyle Polo came to China by land, and after spending more than 20 years in China, he returned by sea. The sea enters the Indian Ocean through the South China Sea, and then turns to the west. Kyle Poirot returned to a ship in China, which was piloted by a China navigator. In the Travels of Marco Polo, the situation of ships and navigation in China at that time was recorded. According to the travel notes, the height of Polaris was recorded after ships entered the Indian Ocean from the Straits of Malacca, which shows that China navigators had mastered star guiding at that time. In the Ming Dynasty, Zheng He made seven voyages to the Western Ocean, "taking the return of the stars as a record". It can be seen that China navigators sailing in the Indian Ocean at that time were already very familiar with the astrology. In the Ming Dynasty, Polaris was generally used to pull the star, but when Polaris was not visible at low latitude (six degrees north latitude), it was changed to pull Capella (Polaris is a star in Ursa minor and Capella is a binary star in Ursa minor).
In the Ming dynasty, azimuth stars were also set up for observation, and the position of ships sailing at night was determined by the azimuth and horizon height of azimuth stars. At that time, it was called stargazing, and stargazing was also within the scope of painting stars.
In the navigation records of the Ming Dynasty, such as the route from Guri (today's Keze country on the west coast of India) to Zufar (today's Zufar in Oman on the east coast of Arabian Peninsula), it is seen that the height of Polaris is six degrees and twenty-four minutes (equivalent to this degree, the same below). The ship sailed 900 kilometers to the northwest to reach Mangjiaonur (now the gate of Gloor on the west coast of India), and the height of Polaris was eight degrees. The ship sailed 1500 km to the west of northwest. At sea, the height of Polaris is 10 degrees. The ship sailed 2 100 km due west to the north, and reached Zufar. The height of Polaris was 12 degrees 48 minutes. The geographical latitude of Polaris height was calculated by the algorithm at that time, which is basically consistent with the geographical latitude of various places now. From the route point of view, the route and voyage are also roughly the same as the dirty road now. It can be seen that the astronomical navigation technology in Ming Dynasty has been quite advanced.
The navigators of the Ming dynasty also had some rules about the time when astronomical phenomena appeared. Among the manuscripts handed down in the late Ming dynasty, there are timetables for the sun and the moon, as well as "songs of the sun and the moon going in and out" and "songs of the lunar calendar going out to work". The "Song of the Sun" is:
"Nine out of nine B's have no Geng Fang; 28 rabbits have no chicken farm;
Sanqi comes from Xin; Four or six students have no dogs to hide;
Go out in May and return to work; In the middle of winter, there is no Fang Kun;
Only in 10 and 12, when it comes out during the day, will it be elaborated in detail. "
This is a Song formula to sum up the solar rise and fall of 12 months. In the first month and September, the sun rises at point B, not at G, point B is between and, and G is between Shaanxi and. The rabbit refers to Shi Mao, and the chicken refers to You. A is between and Xin is between You and Qi. When the dog's fingers are licking. When the weather is dry, it is between ugliness and time, and between uniformity and time. Xun is between Ji and Kun is between Wei and Shen. May is the month of summer solstice, so the sun rises early and the rest rises late. Midwinter is 1 1 month, which is the month of winter solstice, so the sun rises late and the money comes early. Compared with the actual astronomical phenomena, this timing has some errors, but it is generally applicable.
According to some nautical books in the Ming Dynasty, ocean-going ships were equipped with various personnel, among whom Yin and Yang officials and Yin and Yang students were responsible for observing astronomical phenomena. In the novel Popular Romance of Western Sanbao Eunuchs, which was circulated in the late Ming Dynasty, it was recorded that "ten members of Yin and Yang Palace watched the stars". He added, "Each ship has three layers of sky boards, and each layer has twenty-four officers and men. They watch the clouds in the morning and the stars at night. Although this is a novel, it also reflects some actual situations in the navigation of the Ming Dynasty.
Geographic navigation technology
The achievements of ancient navigation technology in China include the invention and creation of navigation instruments such as navigation compass, log and bathymeter, and the use of needle tracks and charts.
The navigation compass was invented in China. After the compass was invented in China, it was quickly used in navigation. The compass in the Northern Song Dynasty, that is, the later water compass. In the Song Dynasty, Zhu He described that compasses had been used on ships from the second year of Song Zhezong Fuyuan to the first year of Huizong Chongning (A.D. 1099 to102). In the fifth year of Xuanhe (A.D. 1 123), Xu Jing described the voyage in the Atlas of Xuanhe's Missions to Korea after he went to Korea. He said: don't stay in the ocean at night, pay attention to the stars and move forward. If it is dark, you can use a floating needle to determine the north-south direction. These are the two earliest records of navigation with a compass in the world, which are 70 or 80 years earlier than the record of 1 180 in Naikim, England.
There are twenty-four directions on the navigation compass, which were recorded in the Han Dynasty in China. These 24 directions were also used on the geographical map of Shen Kuo in the Northern Song Dynasty. Divide the compass 360 degrees into 24 equal parts, and the interval of 15 degrees is always, also called straight needle. But there is a sewing needle when it is used, and the sewing needle is always between two straight needles, so the navigation compass has 48 directions. Probably in the Southern Song Dynasty, these 48 directions were invented. The interval between the 48 directions is 7 degrees and 30 minutes, which is much more accurate than the 32-azimuth compass in the west. Therefore, although the knowledge of the 32-way compass was introduced from the west in the late Ming Dynasty, navigators in China have always used our inherent navigation compass.
The place where the compass was put on the ancient ship was called the needle room, and the general staff could not enter it casually. The man in charge of the compass is called the fire chief. In the Ming Dynasty, it was said in Fan Zhi of West Guo that a pilot with sea experience should be selected as a fire chief and used as a boatman, and then he was told to master management with the Illustration of Needles and Classics. "This is a great responsibility, so don't neglect it." It can be seen that the navigation compass is an important equipment on the seagoing ship.
Logs are also called logs. During the Three Kingdoms period, Wu sailed to the South China Sea. Someone wrote the book Foreign Bodies in Zhou Nan, which recorded that a piece of wood was thrown into the sea at the bow, and then quickly ran from the bow to the stern to see if the wood chips arrived at the same time, so as to measure the speed and voyage. This is the prototype of the log. This method was still used until the Ming Dynasty, but it was more specific, that is, one day and one night were divided into ten shifts, and the time was calculated by the number of branches that lit incense. When people are thrown into the sea, from the bow to the stern, if people and sawdust arrive at the same time, the count is the standard. If you arrive first, you can't get the watch, and the sawdust calls first. One is a 30-kilometer voyage. In this way, the speed and range can be calculated.
This method of log in ancient China is similar to the structure of sector log in modern navigation. Fan-shaped logs are also made of wood (fan-shaped), but they are tied up with swimming lines as long as the whole ship and thrown into the sea, and then the time is calculated with a sand meter. When the sand timer goes backwards, it is fourteen seconds. The swimming line is marked, and the speed and amplitude can be calculated from the length of the swimming line. In ancient China, incense sticks were used, while in modern western countries, sand timepieces (also called hourglasses) were used. The two are really similar.
At the latest in the late Tang Dynasty, China had sounding equipment. One is the "lower hook" sound, and the other is the "iron knot" sound. The depth is over 60 feet, and it is still shallow water sounding. Soon, the outline was recorded for water sounding. "The outline is more than 50 feet long before reaching the bottom." The outline is a big rope, more than 50 feet long, which is already deep-water sounding.
At the end of the Southern Song Dynasty, Wu wrote in Liang Lumeng: If you go abroad to do business by boat, you can go abroad from Quanzhou. After seven continents, "the water depth measured on board is about 70 feet." At that time, the bathymetry was so deep that it can be seen that China had relatively skilled bathymetry technology in the Song Dynasty.
The design of needle track was already available in Song Dynasty. Navigation is mainly guided by compass, so it is called "needle track". There is a book dedicated to recording railways, which has accumulated over time during the voyage. These specialized books were later called "Acupuncture Classics", "Acupuncture Manual" and "Acupuncture Strategy".
Generally, all directions should be stated: sailing to a certain place, route, voyage, and ship to a certain place. The name of the course is as follows: one-way, called single needle (also called single needle), or straight needle. Two-way, called adjacent two directions, is the sewing needle mentioned above. When the two directions are combined, there are four situations: one is one-way first and then two-way; Second, first two-way and then one-way; Third, both are one-way; Fourth, both are two-way. There are more than two directions together. The voyage was calculated at a higher speed. When a ship arrives at a certain place, it is called by four different names: first, it means flat and alongside; Second, the significance of taking and transmitting; Third, the meaning of seeing and not seeing; Fourth, the meaning of receiving and arriving. When the ship sails at night, it is necessary to write down the record of holding the star into the needle track. During the voyage, we must constantly measure the water depth and write it into the needle track.
Now, let's take an example of the needle route from Taicang to Japan recorded in the map compilation of the Ming Dynasty: "Taicang Port sailed with one needle and one meter, and the ship leveled the Wusong River. Use single needle and second needle, Geng Yi, Pingbaoshan, to Nanhuizui. Take the needle of B Chen to leave Hong Kong, draw water 1670 feet, sand and mud as the right path, and see Chashan at night. Since then, Shen Kun and Ding Wei have been in the third watch. The ship has reached the size of seven mountains, and Tanshan is in the northeast. The water depth under the beach is 78: 2, and the ship arrived at Huoshan after midnight with a single needle and a tripod needle. ..... "This passage is not difficult to understand. At present, several manuscripts of stitch, including eastern and western manuscripts, have been found, which need our further study. /kloc-When the Portuguese sailed in Southeast Asia in the early 6th century, they copied the needle track used by China navigators.
As for nautical charts, there is a hydrological chart in Xu Jing's Map of Xuanhe Korean Mission in the Northern Song Dynasty, which is the earliest nautical chart record in China. Unfortunately, the original map has been lost. The earliest existing hydrological map in China is the Hydrological Guide Map engraved in Hydrological Classic in the early Ming Dynasty.
Mao Ming Yuan Yi compiled 240 volumes of Military History. At the end of the volume, there is a picture of "Zibao Shipyard Sailing to Foreign Countries from Longjiang Pass", which is the famous "Zheng He's Navigation Chart". The geographical location of navigation on the map is consistent with that of Zheng He's last voyage to the West recorded by Zhu Yunming (1526) in the fifth year of Xuande (A.D. 1430) in Ming Dynasty. It is speculated that this map is probably a work of1mid-5th century. Zheng He's Nautical Chart is well-known at home and abroad, which is regarded as an important basis for studying the history of transportation and navigation technology at home and abroad in the fifteenth century.
At the end of the Ming Dynasty, some ancient books recorded the Mountain Water Potential Map of Shallow Sediment Reef in each State, Mountain Water Potential Map from Lingshan to Java Island, Mountain Water Potential Map from Java Island to Niecijiashan in Xincun, Pengkeng Mountain Water Potential Map and so on. These maps only keep written records, but the original maps are lost. From the written descriptions of these charts, we can see that marine disasters (such as "Cao Yu" and "Ludi"), shoals (such as "shallow in the bay can be prevented" and "shallow in the mud"), reefs (such as "reefs in the harbor are not allowed to enter" and "reefs make waves") and sandbars (. These generally meet the requirements of modern nautical charts.
The nautical charts preserved in the early Qing Dynasty include a directional chart of the southwest ocean and a colored paper, dating from about 50 to 54 years of Kangxi (A.D. 17 1 1 715), as well as navigation charts of East Asia and South Asia, dating from about 5 years of Kangxi.