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.
"Bragging." Yan Jianyihai directly denied it. Unlike her master, Li Huamei often travels in East Asian waters. Her captain mainly goes to Goa and sometimes Manila. With the help of the windows of these two colonial cities, most Europeans
She had seen all kinds of new gadgets, but she had never heard of any navigation instrument that was more useful than the quadrant.
"Haha, there are so many things you haven't seen before. What's a sextant?" Lin Chuanqing looked indifferent.
Li Huamei saw a place that seemed to have a lens embedded in it. She 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 was particularly tall. He looked at least six feet seventy-eight (1.9 meters).
, is a head taller than everyone around her, has a strong body, a round face and big eyes. She is wearing a blue double-breasted jacket that Australians often wear - they call it a training uniform, and someone once told her: blue
The navy one, the gray one from the army, and the colorful ones are worn by everyone. The skin is dark and thick, and it can be seen that it has been baptized by the sea wind and waves, and the 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 complexions, but stood very firmly on the swaying deck. They all had a green canvas schoolbag on their shoulders.
, stood neatly in a row.
"Commissioner Chen, are you teaching children again?" From the fact that Lin Chuanqing greeted him first, this person should be a relatively high-level shorthair.
"Yes, these children from the sailing class have rowed boats in Bopupu, and this time they come out for an internship."
He came 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 it."
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. How do you want to become a navy after just throwing it away like this?!"
"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 his best to stand at attention and salute, but felt his stomach was churning again, and he walked to the side of the ship again.
"Do you know how to use a quadrant?" Chen Haiyang turned around and looked at the woman in front of him. This was the first time he had actually observed this woman at close range. According to modern standards, she was not short, at least 165cm, which was taller at the time.
She is tall and tall, with her hair thinned and tied into a bunch on the back of her head. At first glance, she does look a bit like a modern woman - no wonder the nerds in the navy are so confused.
"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 in 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 flicked 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 motorboat and sailboat. Do you still need someone to teach you this?"
"After all, a sailboat has an engine." 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 large in size and volume.
"This is my complete set of instruments." She opened it.
In the box were several instruments, books and volumes of charts.
"There are still a few things on board the Hangzhou. They are all fixed, so there is no need to bring them."
Chen Haiyang watched with interest the first thing she took out. This thing was quite large and made of bronze. Its radius was about 0.6 meters. It was cast in bronze and hollowed out in the middle. There were angles engraved on the outer side of the quadrant.
, the minimum scale is 0.25 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. Two copper rings are mounted on a straight edge of the quadrant.
A copper block with two round holes about 5 mm in diameter on it. You can use your eyes to locate the stars 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, and
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 device? I don't know about this. Everyone calls it the British quadrant. But this one is really easy to use and has high accuracy."
The British Quadrant. Chen Haiyang thought this was really intuitive - it was invented by the British navigator John Davis.
"I can't see the astrolabe now. I'll demonstrate it to you in the evening. 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.
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During operation, the observer faces away from the sun and aims at the horizon through the narrow slits on the sighting device on the large arc angle device and the sighting device on the small arc angle device. Set the projection sight and adjust the sight by estimation.
Until the upper shadow falls on the upper edge of the narrow slit, the horizon can be seen at the same time. The sum of the readings on the two arc protractors is the vertex distance. Then the specific latitude can be known through the calculation of the formula. Because of the great circle of this instrument
The arc is divided diagonally, and even a small angle can be read accurately. This greatly improves the accuracy of latitude calculation.
Li Huamei did the operation directly, and then asked the naval cadets to operate one by one, and let them calculate the latitude. Although most of these children came from maritime families, they were almost all illiterate, let alone mathematics. Relying on the evil skills of the national school
After supplementing the knowledge, naturally the calculations were very slow. Several people measured and calculated, and the answers 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, and there were no problems with the observation numbers and calculation process. It seemed that the students' understanding was generally quite good. After all, in the previous shore teaching, they had already put things like: earth, longitude and latitude
, the professor instilled jet lag and basic knowledge of geography and astronomy into the students. Otherwise, just talking about the concept of latitude would make people anxious to death.
"They know the longitude and latitude?" Li Huamei was a little surprised. Almost no one in the Ming Dynasty understood this concept, even people who lived on the sea every day didn't know it, and they had no interest in knowing it - 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 think of more than ten people in Ming Dynasty who know what longitude and latitude are." She felt suspicious. These Australians always said that they were immigrants from the Song Dynasty who were lost overseas in Australia. How could they know about Europe since they were alone overseas?
What about science? There are also these instruments. It seems that they have been communicating with Europe. But Europeans have never heard of this place. It is really strange.
What was taken out next was a small bronze plate with scales, small holes and pointers on it. The edge was zigzag, which looked a bit like a circular saw blade at first glance.
"Night timer. But it can't be used now. It won't work until midnight."
"Using the punctuality of stars passing through the meridian to determine midnight time?" Chen Haiyang speculated.
"You're really good, you can tell right away! 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 is not bad. The title of the book is understandable.
"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 the Australians want to build a country 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 suitable for every quarter of the compass access scale and every degree, as well as logarithmic tables of natural numbers and trigonometric functions.
The Tide Table 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 and Chen Haiyang couldn't understand it, so he had to rely on Li Huamei to explain.
This book is called "Regulations for the Operation of Astrolabes and Quadrants". Its purpose is to provide a reference table for increasing latitude and longitude. Whether the longitude and latitude are determined by the sun or stars, it is necessary to relate the change in latitude to the sailing distance. Sailors
There is a distance table. It is usually affixed to each position of the compass to increase or decrease the longitude and latitude. The book includes the distance table, a latitude table from the end of the earth to the equator, and the solar declination with a 4-year cycle.
Table. This book was published as a guide for pilots. It has a very long history. It was officially published in 1509, and the early version may be earlier. At least Columbus used this book when he sailed in 1492.
It was subsequently revised and republished.
Chen Haiyang flipped through these manuals and looked at the numerous principles and numerical tables on them. How great human beings have made in order to break through their own regions and explore new worlds. Although these manuals look rough, some of the principles and numbers are even
It is wrong, but it is accumulated by the 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 her 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. When Chen Haiyang was not paying attention, they all looked around.
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 in accordance with the latest scientific and technological achievements of this time and space. Medieval charts were flat. This chart was originally a compass line pattern developed for medieval Mediterranean charts.
All north-south lines drawn are parallel, and as the distance from the equator increases, the east-west distance becomes more distorted. The result is that the directions on the chart often have large errors. Mercator invented a new
Projection 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 Asia, Southeast Asia, and the Indian Ocean. Of course Chen Haiyang knew the value of these charts, which were a huge wealth 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 in the Qiongzhou Strait on his own sailboat. For this kind of person