However, even though the animal enclosure wasn't completed, Chen Zhou successfully finished another long-delayed project—the watermill.

...

The rainy season of 1663 was unexpectedly accommodating, with heavy rains spanning several days sometimes, while on other days a light morning drizzle cleared by noon.

Taking advantage of these occasional and brief sunny spells, Chen Zhou led the native workers in constructing a wooden and stone structure by the river channel.

...

The official start date was February 22nd.

Chen Zhou initially planned to build the foundation directly in the water, then construct the entire mill.

However, after walking along the river channel several times, he couldn't find a suitable construction site.

To ensure strong waterpower, the water flow needed a drop, deep and swift enough, but most of the Rock River's channel was relatively wide and flat, with overall slower water flow. While it could drive a waterwheel, it didn't meet Chen Zhou's requirements.

As for other rivers, they were too far from the fields.

Of course, the island had numerous small rivers, mountain streams, and even brooks, and among them were indeed a few suitable for building a watermill.

For example, a mountain stream above a deep pool, rushing down with sufficient speed to support the waterwheel's operation.

Yet, Chen Zhou ultimately didn't choose the mountain stream.

Firstly, because it was located above the Broken Cliff, with only rugged mountain paths for transporting materials, making transportation inconvenient.

Secondly, because the mountain stream was greatly affected by the rainy and dry seasons; the water was turbulent in the rainy season but could easily breach embankments.

Once the high-to-low water flow on the mountain became too large, it could easily accumulate into a flood, destroying everything along the riverbanks. Building a watermill here was unsafe.

During the dry season, especially from mid-April to mid-August, the mountain stream would enter a low-water period, rendering the watermill almost useless, forcing grain processing by manpower.

These two fatal flaws forced Chen Zhou to abandon the mountain stream and choose a more laborious method—an artificial canal.

...

Under Chen Zhou's directive, the native "construction team," already experienced in construction, efficiently dug a canal with a drop, deep enough and of moderate width, at a chosen location beside the Rock River.

The canal was shaped like the letter "C," connecting two parts of the Rock River channel.

After the excavation, Chen Zhou did not immediately breach the soil separating the canal from the river, opting to first build the mill and assemble the waterwheel.

The mill's base was made of pure stone bricks and white clay, with a stone wall foundation exceeding 1m high to ensure the mill's solid durability.

Above the stone wall base, a wooden framework was constructed, and finally, 45° slanted wooden planks were laid on the roof for drainage.

The mill's design was relatively broad, square, and simple to the point of being plain, resembling a clumsy short and stout figure.

Inside this "short and stout figure" were the waterwheel parts Chen Zhou had forged long before, finally ready for installation today.

The mill consisted of two areas: a "waterwheel area" submerged in the canal, at the lower level.

The other was an operation area utilizing transmission devices to grind grains, located on the upper level of the mill.

Time was pressing, so Chen Zhou only managed to produce the grinding millstone for flour, leaving grain dehusking to be slowly processed by the natives using traditional methods.

Dehusked wheat was fed into the funnel above the grinding operation area, entering the grinding millstone below, which operated continuously for ten to even twenty hours or more, after which it flowed through a flour collection trough into pre-placed containers.

The watermill's rotation was not fast, limited by the water flow force, estimated to turn the millstone only 15~20 times per minute.

Yet it boasted endurance and ease, as long as the river flowed, the millstone kept turning, producing flour of comparable quality to that ground manually over extended periods.

Moreover, when designing the millstone system, Chen Zhou incorporated a clearance adjustment structure between the upper and lower millstones, inspired by Chinese watermills, to control the flour's fineness. If coarser grain was desired, the millstone clearance just needed adjusting.

...

Aside from being labor-saving and convenient, this significant structure made entirely of metal was also easier to maintain.

After each grain processing, any residue between the grinding grooves needed to be cleaned out, and every month or two, some animal fat required applying to the waterwheel bearings to prevent rust.

With such maintenance, the waterwheel could remain in normal working condition.

As for inevitable wear over time, that was unavoidable.

If the transmission gears or submerged wooden teeth were damaged, the only option was to disassemble the waterwheel area and replace the parts.

However, the waterwheel was newly built, and Chen Zhou estimated that the first parts replacement would not be needed until at least August or September 1664, or possibly early 1665 if well maintained.

...

On February 27th, the watermill was officially declared completed under the concerted efforts of Chen Zhou and the native workers.

The native workers crowded in the upper work area of the mill, which had not yet opened to water, examining the adjusted millstones with faces full of bewilderment.

Understanding simple tools like shovels and picks was not difficult for them.

But when faced with various transmission gears, bearings, and simple mechanical structures, their minds seemed slightly overwhelmed.

At this moment, Chen Zhou stood beside the flour collection trough of the millstone, with the natives' "idol" Sunday and their teacher Saturday standing nearby.

All non-pastoral natives on the island had gathered, but with the Leader and Sunday present, the atmosphere was serious. Even though everyone had their questions, they dared not discuss them.

They could only stand blankly in place, watching Chen Zhou's back and everything in the room, as if trying to decipher some mystery.

...

Chen Zhou did not intend to exhaust himself explaining the waterwheel's working principle and the functions of each part to the native workers; he knew it would be futile.

He conducted a meticulous check of all the structures in the upper work area, ensuring there were no problems before leading Saturday and Sunday down to the lower level via the indoor staircase.

Throughout this process, he quietly and as thoroughly as possible explained the waterwheel's principles to the two.

Having seen the waterwheel's design and played with the model beforehand, both Saturday and Sunday, with their astute intelligence, already understood the concept to a large extent. Seeing the actual object quickly helped them grasp the essentials.

After explaining how to dismantle and repair the waterwheel's parts to the two, Chen Zhou led them back to the upper level and then announced the breach of the final "barrier" separating the river and the canal, allowing the mill to officially enter its working phase.

...

The manually excavated canal was nearly two meters deep; to prevent early erosion by river water, wide wooden planks were braced at the canal's bottom.

Three proficient native swimmers were tasked with performing this dangerous task.

They removed their shoes, bared their torsos, cinched their waistbands, and, armed with picks, jumped into the shallow accumulated water in the canal. 𝗳𝗿𝐞𝕖𝘄𝗲𝕓𝗻𝚘𝚟𝕖𝐥.𝚌𝕠𝕞

Once they removed the stakes supporting the wooden planks, they used picks to chisel away the earthen wall bit by bit.

As river water began to jet out from the base gaps of the gradually collapsing earthen wall, the three hurriedly threw their picks onto the canal's edge and climbed up using hemp ropes thrown down by other natives, bracing against the canal wall.

Though they were frightened internally, the wall's collapse wasn't that swift.

After about four to five minutes, those small gaps slowly connected, forming a bowl-sized opening.

Soon, more and more soil was eroded by the river, drifting within the canal.

Immediately after, the opening expanded visibly, triggering a chain reaction that led to the upper wall's collapse.

Once a noticeable gap appeared in the upper wall, the pent-up water surged into the canal with unstoppable momentum.

Yellowish-brown blocks tumbled in the torrents.

The gap was soon submerged by the water flow, leaving those on the bank unable to gauge the remaining height of the earthen wall, only able to watch the canal's water level rapidly rise.

The native workers ran along the canal, witnessing the gradual movement of a large and sophisticated vertical waterwheel.

Like a monster coming back to life, the entire watermill instantly brimmed with vitality, breathing like a living creature.

The sound of water was pleasant as the interlocking transmission structure propelled the grinding millstones inside the working area.

...

When the native workers re-entered the upper work area of the mill, they were astonished to see the massive millstone, which required four people to lift together, moving on its own.

At that moment, standing before the millstone, the Leader, Sunday, and Saturday displayed no shock or fear, instead, each wore a smile, chatting casually, unfazed by the phenomenon.