Chapter 2: Star-gauging Technique
Lin Qian had his subordinates handle the corpses and the bloodstains on the deck, and ordered the Fuchuan Ship to turn due south, sailing away from this sea area.
The ship workers followed their original divisions of labor, weighed anchor and hoisted sail, and soon the sound of waves slapping against the bow came.
Suddenly, a muffled voice said: “Lin Laodi, Macau is to the west, why go south?”
The speaker was a man with a Shandong accent, wearing only a single pair of trousers in the biting sea wind, with his sturdy upper body bare, looking particularly conspicuous.
This man was called Lei Sanxiang, third in age among the seven sworn brothers.
Seeing Lei Sanxiang approach Lin Qian, Bai Langzai also drew closer, placing his right hand on the knife hilt behind his back, staring closely at him.
“We’re not going to Macau anymore.” Lin Qian said calmly.
Lei Sanxiang frowned, took a step forward, and shouted: “What do you mean? The ship’s manifest says Macau.”
“Don’t worry, Third Brother, heading south from here, at most twenty days of voyage, and we’ll reach Luzon, which is a Franks’ colony. I’ve been there before; selling this ship’s goods there can double the profit.”
Lei Sanxiang’s brows relaxed after hearing this, but he still said uneasily: “But the ship’s manifest…”
Lin Qian stared at Lei Sanxiang for a moment, then smiled: “Third Brother, do people like us care about the ship’s manifest?”
Lei Sanxiang was stunned by these words, then thought about how they had just robbed the ship, scratched his head, and laughed: “True… Lin Laodi’s brain is the sharpest. I’ll get back to work.”
Lin Qian pulled him back: “When we just took sides, thirteen people hesitated unusually; they were forced to join. Third Brother, keep a close eye on them…”
Then Lin Qian listed the names of these thirteen people.
After several days on the ship, Lin Qian had already memorized the names and appearances of everyone on board; this was a skill he had honed in his previous life when starting from nothing.
Lei Sanxiang noted down the names, responded, and went off.
After he left, Bai Langzai also released his hand from the knife hilt and stepped back.
Lin Qian clearly saw the actions of Lei Sanxiang and Bai Langzai with his peripheral vision.
These seven people did not know each other before boarding the ship, and even now they had not figured out each other’s backgrounds; though they had sworn brotherhood, they were still wary of each other everywhere.
Human hearts are dens of demons!
Lin Qian shook his head, stopped his random thoughts, and ordered the ship workers who had taken knives to be promoted to foremen.
These people sided with Lin Qian the fastest, whether out of anger at the ship captain’s exploitation or greed for silver; at least they were more loyal than ordinary ship workers and could supervise the ordinary ship workers.
At the same time, the ship workers who took knives were dispersed throughout the ship, making it inconvenient for them to gather and plot to overthrow him.
The Fuchuan Ship sailed south for two hours; Lin Qian ordered sails lowered and anchor dropped, ship workers returned to cabins to rest, and the ship captain’s alcohol was distributed to the ship workers.
The ship workers received the alcohol and happily returned to their cabins. They had just gone through a bloody night, mentally tense, and alcohol was the best anesthetic.
Moreover, nighttime navigation has poor visibility and is extremely prone to getting lost, so in these times, when going to sea, ships generally stop at night to rest and sail only during the day.
After watching the ship workers return to their cabins, Lin Qian turned and entered the ship captain’s stern cabin.
Seizing the ship successfully was only the first step of the plan; he was still far from being able to relax.
Compared to the crew cabins where more than a dozen people squeezed into three layers of bunks, the stern cabin was exaggeratedly luxurious, with vast space and all kinds of furniture, no different from a wealthy landlord’s bedroom on land.
Lin Qian searched through the boxes and wardrobe.
He found a box of silver, about one hundred taels, the ship captain’s private property.
At the bottom of the silver box, pressed under it, was a ship’s manifest, detailing the ship’s size, personnel, goods, and other information, with “Macau” as the destination port particularly eye-catching.
Compared to Macau, going to Luzon Island was risky, but for Lin Qian, the benefits were not just making a bit more silver.
Although Lin Qian said verbally that after dividing the silver, everyone could leave freely, Luzon Island was isolated overseas, and the crew members wanting to return to Great Ming had to sail back with the ship.
Once back on the ship, not letting them go would not count as breaking his word.
Unfortunately, to go to Luzon, there was still an important item he hadn’t found—the star-gauging board.
Unlike Great Ming captains who navigated by compass rhymes, Lin Qian did not have the skill to reach Luzon just by a few rhymes and experience; without the star-gauging board to determine latitude, once entering the outer seas, he would be like a headless fly.
Therefore, Lin Qian searched the room inch by inch carefully again.
Half an hour later, he indeed found a cavity under one of the planks.
Lin Qian pried open the plank with a dagger, and by candlelight, he couldn’t help but laugh wryly.
Under the plank were stacked an astonishing number of “small gadgets”; just the protractors alone included straight, curved, spiral, wooden, and jade ones of several kinds.
Besides these, there were all kinds of jade rings, sulfur rings, sheep’s eye rings, and many things Lin Qian couldn’t name.
The few protractors on top still had faint fishy water stains on the surface.
Lin Qian cursed inwardly in disgust and covered the plank back.
Now, the ship captain’s room had been thoroughly searched; the navigator’s room still needed searching.
The navigator was like a modern navigator, his cabin also below deck, near the bow.
The ship’s navigator was the ship captain’s confidant, carrying a knife, so he was killed by Lei Sanxiang at the start of the ship robbery; in his view, since Macau was all the way west along the coastline, there was no need to keep the navigator alive.
Lin Qian took a knife and went out, but as soon as he pushed open the door, he saw a figure outside, immediately stepped back, and held the knife across his body.
“It’s me.” That figure said.
By moonlight, Lin Qian saw that it was Bai Langzai.
Lin Qian lowered the knife, kept a safe distance, and softened his tone: “Why aren’t you sleeping?”
Bai Langzai was expressionless: “Guarding for you; these people can’t be trusted.”
Lin Qian smiled: “Appreciated.”
“Don’t misunderstand; it’s just for the silver. If you die, it’ll be trouble.”
Although the tone was cold, to Lin Qian, this bluntly helping him for silver was far more trustworthy than others’ brotherly pretenses.
“Good, then come with me to the navigator’s cabin.”
Bai Langzai said nothing and silently followed behind Lin Qian.
At the bow, Lin Qian went below to the cabin to search, while Bai Langzai guarded on the deck.
After the time of burning one incense stick, Lin Qian came up from the cabin hugging a stack of wooden boards, with a yellowed booklet tucked in his waist; this was the star-gauging board he was looking for.
Lin Qian carried the star-gauging board to the bow and stacked the wooden boards from largest to smallest, like a pyramid.
He picked up one wooden board, stretched his arms straight, aligned the bottom edge of the board with the sea level, and then looked for the North Star.
Seeing the North Star still some distance from the top edge of the board, Lin Qian switched to a larger board, until the North Star perfectly appeared at the top edge of the board.
Then, Lin Qian took out the yellowed booklet and looked up the data.
Bai Langzai was one of the Tanka People, very curious about navigation; seeing this, he couldn’t hold back and asked: “You know the celestial navigation technique?”
“Mm.” Lin Qian flipped through the booklet and responded casually.
Shock flashed in Bai Langzai’s eyes.
In Great Ming, the celestial navigation technique was a navigation secret art, said to be the method used by the Three Treasures eunuch for voyages to the Western Ocean.
The Tanka People lived on ships and should need the celestial navigation technique the most.
But this art was closely guarded and not transmitted, and since Tanka People were lowly registered in Great Ming, they had even less chance to learn it.
Lin Qian flipped through the pamphlet; according to the star-gauging board used, corresponding to the North Star height here being twelve fingers and one horn, while Macau port’s North Star height was twelve fingers, it could be inferred that this place was approximately 23 degrees north latitude.
After simple verification calculations, the result was basically accurate.
Compared to the sextant, the star-gauging technique’s precision was still slightly lower, but sufficient to navigate to Luzon.
Lin Qian looked up and met Bai Langzai’s gaze; with a thought, he roughly guessed what he was thinking and smiled: “Want to learn?”
The star-gauging technique, mysteriously revered in Great Ming eyes, was to Lin Qian merely a simple application of trigonometric functions.
Specifically, knowing the lengths of two legs of a right triangle, use the arctangent function to find the angle; the formula is θ = arctan(b/a), then use Taylor series for an approximate value.
Since the North Star is on the extension of Earth’s rotation axis, no need to consider seasonal factors; the calculated rough angle is the current latitude.
The navigator’s pamphlet recorded the wooden board models for observing the North Star at different latitudes.
Most Great Ming crew members did not understand trigonometric functions, but by matching the wooden board model with the pamphlet, they could roughly determine the latitude.
