It is not only the design and production of water mills, but also the bellows of hydraulic push-pulling.

Thanks to the junior high and high school physics teachers, it is precisely because of the physics knowledge they teach that Su Yan was able to make the water mill and hydraulic bellows in only five days, of course, the water mill and hydraulic bellows are small-scale model structures.

The speed of making the water mill and the hydraulic bellows is much faster than the previous construction of the bellows, in fact, the structure of the water mill and the hydraulic bellows are more complex than the structure of the bellows.

As for why the design and manufacture of the bellows takes longer than the design and manufacture of water mills and hydraulic bellows, there is a question of ideas.

In ancient China, water mills and hydraulic blower equipment appeared earlier than bellows, and later unexpectedly created bellows, a better blower equipment.

Sometimes a problem of thinking will bother people for a long time, or even a lifetime can not break through this idea, obviously, Su Yan was troubled by a problem of thinking when he designed and produced the bellows before, and it took more than a month to solve.

When it came to the design and production of the water mill and the hydraulic bellows, although the structure of these two hydraulic machines was more complicated, Su Yan did not encounter any problems, so it took a shorter time to produce the model structure.

In the next ten days, Su Yan took the five full-time carpenters' clansmen to make an enlarged version of the water mill and hydraulic bellows, standing by the river, the most conspicuous of which are the two water wheels that stand tall, the role of this water wheel is to convert water energy into mechanical energy, which is an indispensable part of hydraulic machinery.

The hydraulic bellows are built on the riverside of the smelting area, and the water mill is built upstream away from the smelting area, when the river water drives the water wheel to rotate, the two hydraulic machines are running in their own way, unless the river stops flowing or the river dries up, or the two hydraulic machines fail, otherwise the two hydraulic machines will never stop running.

In the time before the arrival of autumn, Su Yan continued to take the five carpenters to drum up the two hydraulic machines, and did not stop until the two hydraulic machines were able to carry out the tasks assigned to them by Su Yan normally.

……

The people of the dragon tribe all know that there is a tribe on the other side of the river, and the first time the people of the two tribes face each other across the river is when Zhi and the exploration team are looking for the big river, and when the dragon tribe moves here, the people of the two tribes will go to the river to fish every day, and the people of the two tribes have seen each other more, and they are used to it.

The dragon tribe is on the right bank of the river, the unknown tribe is on the left bank of the river, the people of the dragon tribe can look at the left bank tribe with a normal heart, but the people of the left bank tribe can't look at the dragon tribe with a normal heart, in the hearts of the people of the left bank tribe, the dragon tribe is extraordinary.

"Obviously they are all primitive tribes, why are you so special?"

Yes, with most of the primitive tribes here, the dragon tribe is too special.

The people of the Left Bank tribe saw that the people of the Dragon tribe were fishing from the river with fishing nets and nets, and they had endless food, but they could only hold harpoons and clumsily fork into the river, and the fishing efficiency was very low, even if their tribe had fish to eat, it still could not make all the tribesmen eat enough every day.

The people of the Left Bank tribe watched the dragon tribe harvest with envy, and they tried to make fishing nets, and took the nets woven with straw rope to the river to try fishing, and after many failures, they still did not give up.

"They" can do it, why can't "we"?

After a period of hard work, the people of the Left Bank tribe finally used straw rope to weave suitable fishing nets, which were much more efficient than spearfishing, but far less efficient than those of the dragon tribe.

Thanks to the increase in food, the people of the Left Bank tribes would go hungry less and less.

With the precedent of fishing nets, the people of the Left Bank tribe became more and more concerned about the dragon tribe, and as the jungle was set on fire by the dragon tribe, the dragon tribe built a new home closer to the river bank, and the sighted people of the left bank tribe were able to see the dragon tribe's new home from a distance.

The people of the Left Bank tribe saw the people of the Dragon tribe planting the land and trees, and they couldn't understand what the dragon tribe was doing, but when the fruit trees planted by the dragon tribe blossomed and bore fruit, they should also try to plant fruit trees artificially.

Now the people of the Left Bank tribe have seen the dragon tribe building earth blast furnaces and hydraulic machinery by the river, they don't know what these things are for, they just observe them curiously, and if they find the use of these things, they will also learn to imitate them.

The people of the Left Bank tribe are paying attention to the Dragon Tribe, and Su Yan is also paying attention to the Left Bank Tribe.

For the people of the Left Bank tribe, a large river at least fifty meters wide blocks the communication between the two tribes and protects their tribe, they do not know whether the dragon tribe is good or evil, but they can observe from daily life that the dragon tribe has a larger population than their tribe.

For Su Yan, the river in front of him was not a problem, with all kinds of metal tools, Su Yan could make a wooden boat to cross the river.

The Left Bank Tribe is one of the goals that the Dragon Tribe is preparing to conquer, but it takes a lot of time to build wooden boats, and the primitive tribes around the Dragon Tribe on the right bank of the river have not been conquered and annexed, and the Dragon Tribe will not waste time making wooden boats to cross the river to conquer the Left Bank Tribe.

The people of the Left Bank tribe did not know that they had been targeted by a powerful tribe.

……

Time passed, and in the blink of an eye, the summer was coming to an end, and the reclamation team led by Zhi and Biao returned together with Team B, who was digging copper ore in the copper mine, and the two teams had a total of more than 240 adult laborers.

"Zhi, where is the road to Yantian now?" Su Yan asked the returning Zhi.

Zhi has been outside for two months, and his face looks like an uncle with vicissitudes.

In the face of Wang's inquiry, he outwitted a map of animal skins, which outlined a simple topographic map, and also marked the names of places such as salt pans and copper mines, and there was a winding line between the salt pans and the copper mines, which was the road from the copper mines to the salt pans, of which two-thirds of the area was two black lines, and the remaining one-third of the area was a black line.

Zhi pointed to the dividing point between the two black lines and one black line on the map and said, "King, we have opened up this road to Yantian here. ”

"Hmm." Su Yan nodded, the two black lines occupied about two-thirds of the total distance, which meant that two-thirds of the road from the copper mine to the salt pans had been carved out.

When it rains, set fire to open up the road, and when the rain stops, Zhi and Biao will lead the team to clean up the road slightly, and the rest of the time is spent mining in the copper mining area.