"Discover the island!"

Almost as the hour hand pointed at 11 noon, the entire "New Hope" sounded loudly with the sound of the looking hand shouting from the top of the mast.

Looking in the direction of my fingers, I vaguely saw the island appearing on the sea level, my face turned a little strange, and even my eyes at Shi Yiwen changed.

He, how did he do it!

How could he be so accurate at sea? Is it because he relies on that sextant?

Faced with such surprise, Shi Yiwen didn't even explain anything. He just smiled, then spread the map and said to himself.

“There is still a little bit different.”

Then, Shi Yiwen used his pen to draw a circle in Keelung and Tamsui in the northern part of Taiwan Island, and then said to himself.

"In the future, you can consider setting up strongholds in these two locations."

Facts outweigh words!

Faced with Shi Yiwen's accurate "prophecy", after decades of sailing experience were completely subverted, *** felt an unprecedented impact, but he also developed a strong interest in this new sailing technique. After all, he knew very well how important it was to find his position on the sea. Of course, the emergence of Penghu Island also made him no longer doubt this new sailing technique.

"General, can the Chief Executive really know where we are at sea?"

Wang Erxi asked curiously.

"You can ask him this."

Looking at the two students following Shi Yiwen, *** said.

"We should indeed ask the Chief Executive Officer for advice."

In fact, *** knew that he should apologize to the Chief Executive Officer. Of course, compared to this, he was more curious about how the Chief Executive Officer knew the position of the ship on the sea. When he took the initiative to ask this question, Shi Yiwen said with the sextant in his hand.

“This is a sextant.”

This sextant was taken out of the library's exhibition room.

"A optical instrument used to measure the angle between two distant targets. It is usually used to measure the angle between the sun or other celestial bodies and the sea or horizon at a certain moment, so as to quickly know the latitude of the sea ship's location..."

The principle of sextant was first proposed by Newton, and of course it has not been invented yet, so it was naturally Shi Yiwen's invention.

"...its components include a small telescope, a semi-transparent and semi-reflective fixed plane mirror, a horizon mirror, and an movable reflector associated with the indicator, an index mirror. The scale arc of the sextant is 1/6 of the circumference. When used, the observer holds the sextant and rotates the index mirror...just like this,"

Shi Yiwen explained while operating the sextant.

"Make the celestial objects that appear simultaneously in the field of view coincide with the horizontal line. According to the angle of the indicator mirror, the height angle of the celestial objects can be read, and the error is about ±0.2°~±1°. The sextant is characterized by lightness and can be observed on swinging objects such as ships. The disadvantage is that they cannot be used on rainy days..."

Finally, Shi Yiwen looked at *** and said.

"How is it? Want to try it?"

The answer is of course yes. When *** learned to use sextant to measure latitude according to Professor Shi Yiwen's method, although his arithmetic was very good, he still could not substitute the formula for calculation for the time being, and it could even be said that he was confused at all. In the end, *** had to give up.

"I can use this, but even if it is measured, what's the use?"

Seeing ***'s confused look on his face, Shi Yiwen just smiled and said to this.

"General Li, using sextant to measure latitude is inseparable from mathematics. In fact, learning navigation itself is necessary to learn mathematics. Sun Jiuliang, please measure our latitude."

"Yes, sir."

Sun Jiuliang is a student of Shitaizhuang Society. Although he has only studied mathematics for less than two years, he is now able to use sextant meter to calculate latitude. After all, he is a "professional" who has been "professional training". However, in just a few minutes, he gave a latitude. Facing the numbers he gave, he asked in confusion.

"Secretary General, what is this latitude?"

Faced with the inquiry of ***, Shi Yiwen explained to him that after all, he would spend most of the time in the future, and these are the knowledge he had to learn and master. In the next voyage, he was over 40 years old, and more often he was like a student, learning about navigation from Shi Yiwen, especially the measurement of longitude and longitude. Two days later, when he spent almost half an hour to calculate the latitude of the ship with the help of a sextant, he asked again in his joy.

"Mr. Shi, now that I have measured the latitude, do you know the position of the ship on the sea?"

"This is just the first step? Look, it's like..."

Pointing at the cloth on the sleeve, Shi Yiwen said.

"Just like these cloth wires, now that we know the latitude, we cannot find the right position we are. If we want to solve this problem, we must also get the longitude, you see..."

He pointed at the fabric and wire warp and weft, Shi Yiwen said.

"This vast sea is like a piece of fabric. As long as we obtain the longitude and latitude, we will naturally know where we are..."

After explaining the latitude and longitude to him in the simplest words, Shi Yiwen spent another half a day explaining to him what longitude is. This knowledge can be said to be extremely novel in the Ming Dynasty in this era. Even in Europe at the same time, it was just beginning to study it.

Faced with this fresh knowledge, he was a scholar himself, and seemed extremely curious. He was eager to learn this knowledge and admired Shi Yiwen even more. After all, these knowledge of navigation was unheard of, and completely subverted his understanding of navigation.

The "New Hope" is not so much an "exploration" as a "coach". The captain is learning new navigation techniques there, and the crew also needs to learn to operate artillery. After all, operating artillery is also an extremely fresh task for them. Sometimes they will throw empty barrels to the sea and then concentrate on artillery fire to bombard it. Although it is difficult to hit a barrel one or two hundred meters away in most of the time, it is certain that if it were a ship,

In this way, on the fourth day after leaving the Taiwan Strait, land once again appeared in the sight of the eye.

"land!"

Accompanied by the shouts of the lookout hand, the sailors who had been sailing in the deep sea for 8 days all became a little excited. When the gray-green land appeared in sight, Shi Yiwen murmured to himself.
Chapter completed!