Day Ten.

Lin Yu'an woke up at dawn as usual. The deep sleep from last night had allowed him to recover most of his strength, but the dull ache from carrying stones still lingered deep in his muscles.

He didn't rush into work immediately but carried out his routine "inspection" first.

There was more and more pack ice by the coast compared to yesterday, crowding the entrance of the fjord like a slowly closing white gate.

The time left for him to gather seafood was running out.

He conducted a scavenging session once again, adding a bounty of mussels and sea snails to his "seafood holding pool."

Then he swiftly checked the traps and fishing devices—still no catches.

He was unconcerned about this; he now had enough food reserves to devote all his energy to the construction of the shelter.

Returning to the construction site, his gaze fell on the neatly stacked pile of timber beside the shelter.

These were the eight pieces of spruce deadwood, cut into three-meter standard lengths with a hand saw, prepared days earlier.

"Everyone, today we start constructing the main structure of the shelter—the wooden walls."

"I plan to make a trapezoidal frame fixed to the top of the stone walls and then gradually add logs."

"But there are two core challenges to building this wooden wall."

"First, how to stabilize the first layer of logs on the uneven stone foundation."

"Second, how to lock the corner logs of the two walls tightly together."

Lin Yu'an decided to start with the longest back wall, the one parallel to the natural rock wall.

From those eight standard pieces of wood, he selected a log with a diameter of about 20 centimeters and dragged it to the stone foundation.

He didn't rush to lift it up but wedged it with two stones first to prevent it from rolling.

Then, he picked up the sharp hand axe.

"To solve the first problem, I must level all the logs that will lie on the stone foundation."

Along one side of the log, he used the axe blade, clang! Clang! Clang!, to chop across the log along a straight line.

More than half an hour later, with the last woodchip falling.

The bottom of the log had been carved into a flat, ten-centimeter wide surface, rough but overall even. 𝕗𝐫𝚎𝗲𝘄𝐞𝕓𝐧𝕠𝘃𝕖𝐥.𝐜𝚘𝚖

He ran his palm over this flat surface and nodded in satisfaction. Then, he flipped the log over, lifted it with effort, and carefully placed it on the stone foundation.

This time, the log no longer rolled. Its massive weight, through this flat contact surface, pressed evenly onto the underlying stone base, as stable as Mount Tai.

Having settled the back wall's base log, it was time for the side wall and the crucial corner.

From the remaining seven pieces of wood, he selected another equally straight one and leveled its bottom in the same manner.

Then, he placed it horizontally at the end of the back wall log, forming an "L" shaped overlap.

Now, he needed to carve a semi-circular notch into the upper side wall log, allowing it to perfectly "saddle" the lower back wall log.

But this needed absolute precision, and without modern measuring tools, the best solution was to replicate the natural shape itself.

He found a Y-shaped slender branch, sharpened its two ends to an extreme, smeared them with charcoal, and slightly spread its feet apart with a short string, securing them tightly.

A simple line marker with a fixed opening angle was born.

He squatted, lowering his body, aligning his sight with the two overlapping logs.

He pressed one sharp foot of the line marker tightly against the rounded side of the lower log. The other sharp foot nudged the bottom of the upper log lightly with its tip.

Then, his body started moving, as he steadily guided the line marker with his left hand, allowing the lower foot to slide smoothly along the contour of the lower log.

This movement caused the upper foot to draw a clear ink line along the belly of the upper log synchronously.

As he moved from one end of the log to the other, a perfect crescent arc was precisely replicated.

"This is the part we need to cut out."

He first used the axe to carefully carve a row of fine V-shaped cuts along the outside of the arc line.

This was not only to determine the depth and boundary of the groove but also to relieve the timber's stress, preventing the wood from cracking elsewhere when sawing.

Then he took out the trusty hand saw, sawing vertically downwards along the arc's two ends.

"Squeak... squeak..."

The saw moved toughly but steadily through the wood, with sawdust swirling like yellow snowflakes.

When the two saw cuts reached the lowest point of the arc line, he switched back to the axe, chiseling away the lumber between the two cuts piece by piece.

As the groove was cleaned out, the most exciting moment came.

He took a deep breath, lifted the prepared end of the side wall log with all his might, aligned it with the end of the lower back wall log, and forcefully set it down!

"Thud!"

A deep and solid sound of collision resounded!

The two massive logs meshed together in an extremely snug way, with the upper saddle perfectly enclosing the round contour below!

The subsequent time was filled with tedious yet rewarding repetitive work.

He processed all of the first-tier logs in the same manner and carefully placed them on the stone foundation one by one.