When Zhang Qin's fleet sailed within a few miles of the island, he could see nearby fishermen fishing in small, rudimentary fishing boats. Pen, fun, and www.biquge.info

The crew of the flotilla curiously lay on the side of the boat and looked at the fishermen on the small fishing boats dozens of battles away.

It is said that the fishing boat is enough to be raised, but in fact it is a raft that is slightly better than a simple raft, and worse than the boats used by the poorest fishermen in the Tang Dynasty.

In the eyes of the crew, the people on the raft were short, shaved (shaved), and wore animal skin clothing, which resembled nakedness.

One by one, the crew sneered at the naked people on the raft, and gestured with their fingers to the size of their birds, comparing them with themselves, and some of them laughed loudly.

The fishermen on the raft also looked at the crew of the three big boats with great curiosity, and when they saw the people on the big boat pointing at them and laughing, they didn't feel that they were wrong, but smiled at the crew of the boat one by one.

What's more, they approached Zhang Qin's big boat with the raft, and their faces were surprised and they kept touching the hull of the big boat with their hands, and they screamed for a while.

"Damn, a bun of dirt buns, I haven't seen the world, if we drive the ignorant giant ship over, we won't scare you all to death."

Wang Haichong, who was lying on the side of the boat, looked at the man who was similar to a savage on the side of the boat with a mocking face, leaning the raft on the big boat and touching the wall of the boat in surprise.

"There is no doubt that this island should be the island where the Danluo Kingdom is located, and the clothing of these people is consistent with Liu Renliang's performance, and there is no resemblance to the clothing and clothing of the Baekje, Silla, and Wa people, and there is no difference between them and the uncivilized savages." Yu Hong said happily.

Zhang Qin and Zhang Mao were even more overjoyed, and the first stop of the trip, Danluo Kingdom, arrived without any danger, which was a good start.

The flotilla found a small harbor to dock, and the crew, dressed in armor and swords and bows, rowed to the shore in small boats.

When the boat docked, the crew excitedly stepped into the water and ran ashore, stepping on the ground with their feet a few times. But they had been adrift at sea for ten days, and the ship was shaky, and after they went out to sea, no one had peace of mind.

In this era, when you go to the sea, you don't pin your life to the waistband of your trousers, maybe you won't be able to come back when you hit the storm one day, but these veterans who have gone to sea this time are still rarely excited every time they dock.

Like one of Yu Hong's personal soldiers, he can swim but has never been out to sea, and he is even more excited than anyone to set foot on land again.

Wang Haichong jumped out of the boat, held his wet trouser robe, and after a moment of excitement with the crowd, he took out a copper gui watch from the small rectangular box he was carrying, which was two feet long.

The benchmark for measuring the shadow of the sun on flat ground is called a watch; The stereotype that measures the length of the shadow is placed flat in the direction of due south and north is called kyu. When the sun shines on the watch, the shadow of the watch appears on the table, and according to the direction and length of the shadow, the time can be read, and the altitude angle of the sun in this place can be calculated, and the latitude of this place can be calculated.

Wang Haichong first used the compass to determine the north-south direction of the place, and when the compass stopped rotating, he determined the north and south according to the direction pointed by the red and blue pointers, and then laid Gui towards the north, took out a small notebook from his sleeve and stared at the scale on Gui and waited for the arrival of noon.

Since the sun moves from east to west, the shadow of the watch is projected on the sun only at noon. In addition, due to the north-south movement of direct sunlight points in the Northern Hemisphere during the Earth's revolution, the length of the shadow at noon in the same place is different every day. According to the law of the change of the length of the shadow, we can know the length of the year and the position of the 24 solar terms.

For Wang Haichong, he only needs to measure the latitude of this place, what is the length of the year, the twenty-four solar terms, and whoever is interested will do it.

He and the other two cartographers in the fleet were responsible for accurately drawing the islands discovered by the fleet on the map, and also drawing sea charts with Zhang Qin and other people who were proficient in navigation. Wang Haichong's main responsibility is to determine the latitude along the way, and as for the longitude, it can only be estimated.

Li Yu, together with Li Chunfeng, Hu Huichao, Ye Fashan, and Wang Haichong, and Ge Xianshi referred to the ancient Roman geoastronomer Ptolemy's Guide to Geography brought by Roman merchants, combined with the works of Chinese ancestors such as Zhang Heng of the Eastern Han Dynasty.

It was agreed that Chang'an should be the 0-degree meridian, that is, the prime meridian, and divided into 180 degrees east longitude and 180 degrees west longitude. At the center of the earth, a 0-degree latitude is drawn as the equator, which is divided into 90 degrees of latitude from north to south.

After verification, it is determined that the distance between the two latitudes proposed by Li Yu is 222 miles, that is, 111 kilometers, and does not decrease with the increase and decrease of latitude.

As for the longitude, it was determined that the distance between the two degrees of longitude on the equator was 222 miles (this needs to be verified, but it is only a hypothesis put forward by Li Yu, although he knows that it is correct, he cannot say the reason, and he can only use the distance between latitudes to assume the longitude to convince Li Chunfeng and others). The distance between the two meridians from the equator to the north and south increases by one degree with latitude, and the distance between the two meridians decreases by about 2.5 degrees to the two North Poles.

Master Wang Haichong, Hu Huichao and Ye Fashan led the astronomical staff of Yanwangfu to measure the straight-line distance from Chang'an to Haizhou on the Yellow Sea after a year of hard work. The latitude of the two places is the same as 34 degrees, according to the distance conversion formula between the two longitudes agreed by Li Yu and others, the two meridians of 34 degrees of latitude are separated by 137 miles, and then divided by the straight-line distance between the two places, it is calculated that Chang'an to Haizhou can be divided into about 14 meridians.

Taking these two places as the standard and combining the distance with Chang'an measured on the spot, the local longitude was estimated from the east, west, north and south of the Tang Dynasty, and then the map was drawn on the graticule map with the measured latitude, and extended to the Andong area.

Wang Haichong's longitude of Danluo is based on this, combined with the longitude of Chengshan and Pyongyang, the easternmost part of the SD Peninsula, and then calculated by using the "dead reckoning method" proposed by Li Yu: that is, knowing the longitude at the time of departure, judging where he has arrived by calculating the sailing time and average speed, and finally estimating the longitude of the place he has reached.

While waiting for noon, Wang Haichong took the longitude calculated by the voyage time and the speed of the ship recorded all the way, and then used the longitude of a few reference places, frowned and calculated a longitude position that he was not too convinced, sighed and wrote down this value, and returned to the ship to mark it on the Datang graticule map after the latitude was measured.

"I'm calculating your unreliable longitude again, according to Poor Dao, it's better to find someone with rich sailing experience to determine the distance between the two places, what you calculated all the way, Poor Dao doesn't believe it."

Uncle Sun Kang held a piece of grass in his mouth, and walked forward with a lot of abuse and mocked Wang Haichong.

"Hmph, you are a lonely and unheard of wild way, how can you be the mystery of astronomy and geography."

Wang Haichong didn't bother to glance at his uncle Sun Kang, such a bickering has not been less since the start of the fleet.

Uncle Sun Kang snorted coldly and ran to look at the curious natives who came around.

The first landing site of Jang Qin's fleet was in the western bay of what was later called Jeju Island, where the Danna Kingdom was located. The fleet stayed here for three days, and Yu Hong, Wang Haichong and others led the team to go deep into the inland to investigate the local customs, topography and soil conditions.

Wang Haichong, who returned three days later, worked with two cartographers to draw a map of the vicinity of the western landing of Danluo. The meandering bays, the undulations of the terrain, the distribution of rivers, and the forest cover are all drawn in detail on the map according to Li Yu's requirements, like the topographic maps of later generations.

The fleet sailed eastward along the coastline, and according to Liu Ren's book, the Danluo Kingdom was in the center of the north of the island.