The Quadrant was born in this time and space less than half a century ago. Now someone is telling Li Huamei that this is better than the Quadrant. Of course she doesn't believe it - it is smaller than the Quadrant. 【Read full text】
"Bragging." Yan Jianyihai directly denied it. Unlike her master, Li Huamei often travels in East Asian waters. Her captain usually goes to Goa and sometimes Manila. With the help of the windows of these two colonial cities, she has seen most of the new European gadgets, but she has never heard of them. There is no better navigational instrument than the quadrant.
"Haha, there are so many things you haven't seen before. What's the sextant?" Lin Chuanqing looked indifferent.
Li Huamei saw a place that seemed to have a lens embedded in it, and was about to touch it when she suddenly heard someone shouting: "Don't touch it, or you may stain the glass."
When I looked back, I saw a man I didn't recognize. He was in his late thirties, tall and big. Short-haired people are generally taller, but this one is particularly tall. He looks at least 6 feet 78, a head taller than everyone around him, and has a strong body. Round face and big eyes. Wearing a blue double-breasted coat that Australians often wear - they call it a training uniform. Someone once told her: the blue one is from the Navy, the gray one is from the Army, and the colorful one is worn by everyone. His complexion is dark and thick. It can be seen that he has been baptized by sea wind and waves, and his expression is stoic and serious.
Behind him were six boys wearing black stand-up collar student uniforms. They all looked to be between thirteen and fourteen years old. All of them had dark faces, but they stood very firmly on the shaking deck. They all carried a green canvas schoolbag and stood neatly in a row.
"Commissioner Chen, are you teaching children again?" Lin Chuanqing said. Since he was the first to say hello, this person should be a relatively high-ranking short-haired person.
"Yes, these children from the sailing class have been rowing boats in Bopupu until now, and this time they come out for an internship."
He walked over, took back the sextant from Li Huamei, and said in a deep voice: "The most important part of this thing is the glass lens. It's useless if you touch the flowers."
Li Huamei said: "I've never seen it before. It's such a rare thing. It's like a treasure."
The strong man ignored her at all. When he saw Mond stumbling back from the side of the ship, he reprimanded expressionlessly: "A sailor's instrument is his life. You just throw it away like this and you still want to be a navy?!"
"Yes, yes, I-" Mond could hardly stand still, but he could see that he was in awe of this man and tried hard to stand at attention.
"Go back to the cabin and disband!"
"Yes!" Mond tried hard to stand up and salute, but felt his stomach churn again, and walked to the side of the ship again.
"You know how to use a quadrant?" Chen Haiyang turned back and looked at the woman in front of him. This was his first time observing this woman at close range. According to modern standards, she is not short, at least 165 meters. She was taller at the time, with a tall figure and a thinned head tied into a bunch behind her head. At first glance, she does look a bit like a modern woman - no wonder in the navy All the otakus are dizzy.
"Of course I can use it. This is the guy who eats." Li Huamei could tell that this was a difficult guy and said sternly.
"Let me use it first." Chen Haiyang is very interested in ancient navigation technology. Many equipment used for modern ship navigation cannot be manufactured in this time and space. How to use the mature technology of modern and ancient times has become a way to train a new generation of sailors. the main topic.
"Okay, I'll go get a box and bring it up." She swung the horse's tail that fell to her ears, "But you have to teach me how to use this sextant later!"
"Okay." The other party answered simply.
"Commissioner Lin, is the sextant okay?" Lin Chuanqing asked his boss when he saw Li Huamei going downstairs.
"It's nothing special. Originally, we had to teach these children." Chen Haiyang said, "Besides, she also teaches us things."
"Well, to be honest, I also want this girl to give me some tips on steering."
"Stop joking, you old smuggler, you dare to cross the Pacific Ocean with a small motor and sailboat, do you still need someone to teach you this?"
"Sailboats also have motives after all." Lin Chuanqing held the steering wheel hard, "This kind of pure sailboat always feels a little wrong in the hand."
As she spoke, Li Huamei climbed up to the stern again, carrying a box in her hand. This box was quite big and bulky.
"This is my complete set of instruments." She opened it.
Inside the box were several instruments, books, and rolls of charts.
"There are still a few things on board the Hangzhou. They are all fixed. There is no need to bring them."
Chen Haiyang watched with interest as she took out the first thing. This thing is quite large. It is made of bronze. Its radius is about 0.6 meters. It is cast in bronze and has a hollow center. The angle is engraved on the side of the outer circle of the quadrant, and the minimum scale is o.25 degrees. There are two copper rings in the center of the circle for hanging. A thin silk thread hangs from the center of the circle, and a lead ball hangs from the end of the thread. There are two copper blocks inlaid on one straight edge of the quadrant, with two round holes about 5 mm in diameter on them. The stars can be located with the eyes through these two round holes.
"This is the quadrant." Li Huamei explained, "Some people call it the ocean astrolabe."
"Wait a minute, I remember the quadrant is not like this." The more Chen Haiyang looked at it, the more he realized that this thing was different from the quadrant pattern he saw when he was studying at the Naval Academy.
"This is the quadrant," Li Huamei said, and then she understood, "You should be talking about the British quadrant." As she said that, she took out an instrument inside and outside, which was much smaller in size and also made of bronze. The sextant is somewhat similar.
"This is obviously a back sight!" Chen Haiyang patted his thigh and remembered the standard name in the textbook.
"Back collimation? I don't know about that. Everyone calls it the British quadrant. But this one is really easy to use and has high accuracy."
British Quadrant. Chen Haiyang thought this was really intuitive - this was discovered by the British navigator John Davis.
"I can't see the astrolabe now. I'll show you how to do it tonight. Let's look at the quadrant first."
Chen Haiyang paid attention to the students: "You all carefully watch Instructor Li's operation!"
"You want me to be the instructor." Li Huamei chuckled, "I'm just going to show my shame." As she said that, she raised the back sight.
The reason why the back collimation instrument is called "back" is mainly because it is different from the right-angle collimation instrument used before it. The two methods of use are similar, the difference is that one needs to observe the sun directly, while the other is just the opposite, facing away from the sun.
When operating, the observer faces away from the sun and aims at the horizon through the narrow slits in the sight on the large arc receiver and the sight on the small arc receiver. Set the projection collimation by estimation, adjusting the collimation until the upper shadow falls on the upper edge of the narrow slit. The horizon is also visible. The sum of the readings on the two arc protractors is the crown distance. Then you can know the specific latitude through the calculation of the formula. Because the large arc of this instrument is divided diagonally, even small angles can be accurately read. The accuracy of latitude calculation has been greatly improved.
Li Huamei performed the operation directly, and then asked the naval cadets to operate it one by one, and asked them to calculate the latitude respectively. Although most of these children come from maritime families, almost all of them are illiterate, let alone mathematics. I only had to supplement my knowledge at the National School, so the calculations were naturally very slow. Several people measured and calculated, and the answers they submitted were quite different from the numbers measured by Li Huamei.
Chen Haiyang looked at the calculations of several students. Some people obviously made calculation errors, but there were no problems with the observed numbers and calculation process. It seems that the students' understanding is still quite good. After all, in previous on-shore teaching, they had already taught students knowledge about the earth, latitude and longitude, time difference and basic geography and astronomy. Otherwise, just talking about the concept of latitude will scare people to death.
"They know the latitude and longitude?" Li Huamei was a little surprised. Almost no one in the Ming Dynasty understood this concept, even people who made a living at sea every day did not know, nor were they interested in knowing that there was another system for ancient Chinese navigation.
Chen Haiyang was a little surprised. Isn't the concept of longitude and latitude the most basic concept in navigation: "I have taught them all, otherwise how can we sail?"
Li Huamei sighed with emotion: "I can't see more than ten people in Daming who know what latitude and longitude are." She felt suspicious. These Australians always say that they are immigrants from the Song Dynasty who were lost overseas in Australia. Since they are alone overseas, how can they know about European science? And these instruments. It's as if they have been communicating with Europe. But Europeans have never heard of this place. How strange.
What was taken out next was a small bronze plate with scales, holes and pointers on it. The edge was serrated, which looked a bit like a circular saw blade at first glance.
"Night timer. But it won't work now. It won't work until midnight."
"Use the punctuality of stars passing through the meridian to determine midnight time?" Chen Haiyang speculated.
"You're really good, you can tell at a glance! Have you ever used it?"
"No, I never thought there was such a thing in the world before you took it out."
"This is a pamphlet for navigation." She took out a book with a rough hard cover that was very worn.
"This is——"
"Seaman's Calendar." Chen Haiyang was a naval officer and his English was pretty good. The title of the book is of course self-explanatory.
"Do you know English?"
"I know a little bit." Chen Haiyang was very humble.
"Haha, it's really amazing." Li Huamei boasted casually, wondering why everyone in this group of Australians knew a few words of English? If Australians want to build a nation through trade, Dutch or Spanish seem to be more useful.
She didn't know that thanks to the universal education and college entrance examination system in another time and space, almost everyone in China under the age of thirty knows a few words of English.
The book contains some astronomical charts that must be used by navigators, mainly meridian charts, distance and sailing charts for every quarter of the compass access scale and every degree, as well as logarithmic tables of natural numbers and trigonometric functions, Tide table. It is a very convenient reference book for sailors.
"This book is only sold in the UK now. It's quite hard to find. I got this book from a British ship last time." It was obviously a trophy.
The other one was printed in Portuguese. Chen Haiyang couldn't understand it, so Li Huamei had to explain it.
The book is called "Rule of Operation of the Astrolabe and Quadrant". The purpose is to provide a reference table for adding latitude and longitude. Whether latitude and longitude are determined by the sun or stars, it is necessary to relate changes in latitude to sailing distance, and sailors have a distance table. It is usually attached to each position of the compass to increase or decrease the latitude and longitude. The book contains a distance table, a latitude table from the End of the Earth to the equator, and a table of solar declination on a four-year cycle. This book was published as a guide for navigators and has a very long history. It was officially published in 15o9, and the early version may be earlier. At least Columbus used this book when he sailed in 1492. It was subsequently revised and reprinted.
Chen Haiyang flipped through these manuals and looked at the numerous rules and tables. What a great effort mankind has made to break through its own territory and explore new worlds. Although these manuals may seem rough, and some of the guidelines and figures are even wrong, they are the accumulation of wisdom and experience of countless sailors. Standing in front of them, I can't help but stand in awe.
Isn't the Li Huamei in front of me one of those senior voyagers? Chen Haiyang, who had always been suspicious and repulsive towards her, felt a subtle emotion in his heart.
The naval cadets were all half-grown children. Although they were bound by strict military discipline, they saw many strange things that they had never seen before coming out of the box. They all looked around when Chen Haiyang wasn't paying attention.
The last thing Li Huamei took out were rolls of paper: "These are nautical charts. They are very expensive." She said jokingly.
These charts are Mercator charts drawn according to the latest scientific and technological achievements in this time and space. Medieval nautical charts were flat. This chart was originally a pattern of compass lines developed for medieval Mediterranean charts, which gave all north and south lines as parallel, with east-west distances becoming more distorted as distance from the equator increased. The result is that the bearings on the charts often have large errors. Mercator invented a new projected chart. The most basic feature of this projection chart, that is, its difference from the plane chart, is that it gives the true bearing or compass bearing line between any two points. The accuracy is greatly improved.
Most of these charts are of East and Southeast Asia, as well as those of the Indian Ocean. Of course Chen Haiyang knew the value of these charts, which were a huge fortune in the past.
“Can I go to Goa?”
"I am on the Goa-Macau route. I have also been to Madras."
"You are really a navigator." He said sincerely. Chen Haiyang is an explorer at heart and a lover of outdoor activities. After retiring from the army, he once crossed the Siguniang Mountains alone and sailed through the Qiongzhou Strait on his own sailboat. I feel a lot of sympathy for this kindred spirit. ! ~!
