How to accurately draw a scroll of mountains, rivers and topography maps, and craftsmen nowadays and their own methods.
The Mo family was a great master. Later Momen declined and craftsmen were separated. It was not until the Wei, Jin, Southern and Northern Dynasties that the notes of Momen scattered in many historical documents of the pre-Qin and Han dynasties were sorted and recorded by later generations and were able to see the light of day again.
During the Wei and Jin Dynasties, Pei Xiu found many useful methods when summarizing the drawing experience of his predecessors. So he summarized the methods of each school and proposed the "six bodies of drawing" and creatively summarized the six principles for drawing maps. They were: percentage, precision, road, high and low, evil, and straightforward.
According to this method, he personally completed the survey and mapping of the "Yugong Regional Map". This is the earliest "Map Album" in China.
"Subdivision" is the scale bar, "sight" is the direction, "dao" is the distance, "high and low" refers to the height difference, "square evil" is the slope, and "turning straight" is the conversion of height and distance.
Pei's six-body drawings were created, which accurately explained the relationship between map scale, orientation and distance, and influenced the map surveying and mapping in later generations.
At the same time, there was also Liu Hui's "Island Calculation" written by him. He used the "severe difference method" to measure the sea topography and topography. It also provided a mathematical foundation for mapping, and was the earliest work of "Measurement Mathematics" in China.
Later, there was Tang Monk "Yixing (Zhang Sui)", who used large astronomical observation instruments and demonstration instruments such as self-made "Zodiac Travel Circle" and "Water Transport Armary Sky Circle" to select several measurement points along the same line south and north of the Yellow River Basin, and measure the height of the North Star at each point and the ground distance between any two points, and calculate the length of the meridian.
The conclusion is that the height of the Arctic is one degree different, and the distance between the north and south is 351 miles and 80 steps different. This is the length of the meridian (131.3 kilometers). Compared with the precisely calculated meridian (111.2 kilometers), although there is an error of 20 kilometers (the error rate is only 0.18), it is still accurate. Therefore, it is called the first person in the world to "accurately measure" the length of the meridian.
In a nutshell, the height of the North Star is the local geographical latitude. Just know the difference between the heights of the North Stars of the two places, and then you can get the length of the meridian.
On the contrary, if you know the length of the meridian and measure the difference in the heights of the two north stars, you can accurately obtain the difference in the latitudes of the two places.
The importance of this result is self-evident.
It also had a profound impact on later generations and map surveying.
First of all, the North Star is still relative to the North Pole. Looking up at the elevation angle of the North Star is the local geographical latitude, so it has nothing to do with measuring the season (please note).
Secondly, the meridian is an equal semicircle with a span of 180 degrees (180°), so the shape of the earth does not affect its measurement (please note again).
Just look up at the North Star on the boat on a clear night and accurately measure the elevation angle, and you can accurately calculate the difference in latitude between the two grounds.
Whether "Sinan" is a compass in the true sense is inconclusive in the future. However, since Liu Bei's "Qilin came to the world", the compass has indeed appeared. All Ji State sea ships have "needle rooms" to be used to resettle "Sinan". Liu Bei ordered Su Bo and others to develop "navideo compass". Materials such as compass, white glass, etc. are all ready. Just integrate the physics contained in it, and it should not be difficult to be born.
The compass in the present is called "天风". It is mostly lacquered wood. It is similar to the "Feng Shui compass" in later generations. It consists of a circular sky plate and a square earth plate. The twenty-eight constellations are engraved on it. The center is connected by an axis. The four corners of the earth plate are connected with the sky plate. There are two lines inlaid with one large and two small, and three bamboo beads for rotation. The structure is complex and exquisite.
Just a little transformation can be made into a nautical compass.
Before the "navigilance compass" appeared, people had used astrological signs to identify the direction.
According to the "Book of Han·Yiwenzhi", in the former Han Dynasty, astrological books could be used as navigation on the sea. There are already twelve volumes of "Stars in the Sea" and twenty-two volumes of "Five Stars in the Sea" and 136 volumes of "Miscellaneous Things in the Sea". They are all astronomical experiences and laws summarized by predecessors at the sea. They record the judgment of constellations, planets and other positions during navigation to determine the route.
However, through the sun or constellation, only the heading can be determined, and the positioning cannot be accurately determined. Moreover, the speed cannot be determined.
As for "tracking stars across the sea" and "lotting ropes and playing festivals", they are still a story. There is no need to sail from a long ocean now. The Japanese archipelago and the Sanhan Peninsula face each other across the sea. Just cross the Tsukuma Strait, even if you encounter hurricanes and ocean currents, with the narrow and long Japanese archipelago, you can finally find the Eima Tai Kingdom.
Just establish a port on Tsuma Island as a relay. The Ji Kingdom's Pastoral Sea Vessel can pass through Quanzhou Port, Namjin Port, Jeju Port, Busan Port, Tsuma Port, and travel between the Sanhan Peninsula and the Japanese archipelago. Calculate the time, the fleet heading to the Ematai will return soon.
Thanks to the surveying and production of Lou Sang's micro model map when he was a teenager.
The good craftsmen of Ji Country can all accurately draw maps based on "one side".
"One zhang horizontally" is called "one square". This is the provincial name of "one amphibition". In other words, reducing "one amphibition" to "one amphibition squarely" is the most commonly used city drawing "partition rate" in Ji State.
This is what the craftsman said: "The earth of one place shrinks slightly between a square inch."
King Ji had long said that. All maps and sea charts in Ji State were "a square of one mile". So, a mile sea chart was drawn in the square of "a square of one inch". It was one of the king's orders that all the sea ships in Ji State were ordered by the king when they went to sea.
How to calculate the speed has become an unsolved mystery that lingers in the mind of King Ji. In Liu Bei's view, the reason why speed is difficult to calculate is because the relative speed of ships cannot be calculated on the vast sea. Unlike land, sea water flows.
Knowing that Liu Bei was at a loss to measure the speed, Zuo Guo Lingshi said: Why not use the "flowing wood method"?
Liu Bei was stunned: Let's go quickly.
The "Flowing Wood Method" was the first "maritime schedule method" created by the ancestors of China. This method was no later than the Han Dynasty and was used in navigation activities.
According to the Three Kingdoms period, Wan Zhen, a native of the Eastern Wu, recorded in "Nanzhou Foreign Objects Records". The specific operation is as follows: one person threw the wooden block into the sea at the bow of the ship, and another person ran to the stern at the same time, ensuring that "people and wood" reach the stern at the same time. In this way, the length of the hull and the running time can be known, and the speed can be calculated and the range can be calculated.
There are two key points: one is to set off at the same time and arrive at the same time; the other is to be able to accurately count the timing. If you use such as "one stick of incense", it is obviously too extensive. If you use missing etching, it is also difficult to calculate the "difference between minutes and seconds".
The high priestess who were careless and had good saliva, also took his busy schedule and said, "Why not use an hourglass?"
A word awakens the dreamer.
Hourglass is not complicated. It is roughly the same as the current leakage carving. As mentioned earlier, white glazed glass and fine sand grains can be picked up at will. The production should not be complicated! Hourglass is easy to carry and not limited by the region. For example, in the cold weather in the north, water drips into ice. The leakage carving cannot be used outdoors. It is not limited by water pressure, and hourglass should be more accurate than leakage carving.
After unlocking the glass firing operation, many creatures came into being.
A glimpse of the picture shows the whole leopard. Let’s see, what is a combination of the East and the West! Western mechanisms also have great tricks. Of course, the knowledgeable high priestess also make an indelible contribution.
King Ji has always been rewarded for his achievements.
Then he hooked his hand and hugged it into the hotbed by the pond.
Chapter completed!