Time flowed like water, and ten days passed in a blink of an eye.

Outside the city of Cold Island, there were already ten more level 5 houses at this time, and the population had also increased by two hundred.

In this recruitment, I was lucky enough to get a level 3 planter, and now I am managing the farmland with Zheng Yuepo.

The newly recruited population is almost all busy in the fields at this time.

Thirty acres of first-class farmland have all been reclaimed, and more than 200 people have been sown, and there are even some shortcomings.

In the barracks, those who were injured, Xiao Han did not give up, and exchanged two four-grade corpse pills for a medicine to treat the rupture of internal organs.

However, it was still a little late, and the others were okay and had slowly recovered, but Hou Xiu's injuries were a little more serious, and even if he took the medicine, he did not survive.

Together with Wang Quan, Qi Lin and others, the second-grade soldiers lost a total of five this time, but fortunately, the first-grade soldiers did not participate in this kind of battle at that time, otherwise there would have been more deaths.

Raba's search for crystallized mud materials has also been rewarded, clay and gypsum have been found, but black crystal has never been found, Xiao Han even suspects that there may not be such a rock on Cold Island.

If this is the case, if you want to burn crystallized mud, you can only go to the Great Forum of the Heavens to buy it.

But for the time being, he didn't want to do this, and he wasn't going to let other lifeforms know about any of the materials that burned the crystallized clay.

Tog carefully analyzed the data of crystallized mud during this time, and according to him, it only took grade 4 fine iron and crystallized mud to build a building up to 500 meters high.

If the metal material used is grade 5 black iron, even if you build a building that is 800 meters high, there should be no problem.

There are huge business opportunities here.

After being promoted to the town, the most urgently needed building on Cold Island was not a residential house, not an arrow tower, not a city wall, but a 500-meter-high stargazing platform.

But the 500-meter-high observatory can't be built with ordinary materials at all, and obsidian must be used.

Because the strength of other kinds of stone is too low, often only one or two hundred meters are built, and the stone at the bottom will not be able to withstand the huge pressure and crumble.

But the price of obsidian is not affordable for ordinary islands.

So in the Great World of the Heavens, there are many substitute products, such as cement that he knows, and lava soil that he has never heard of, green gel, and so on.

Although these alternative materials do not make for the construction of a 500-meter-high observatory, they are not completely useless.

For example, the ultimate height of green gel is 300 meters, and if it is forced to be built to 350 meters, the biggest possibility is that the bottom base cannot withstand the pressure and collapses.

Lava soil is the same as cement, but the limit height of these two materials is about 400 meters.

In fact, such a height is completely sufficient for many islands, and it is not necessary to build a 500-meter-high observatory.

As a result, the supply of these materials exceeds the demand.

However, the islands where these materials are purchased are often only level 1, 2, or 3 towns, and after level 4 or 5, the height of three or four hundred meters is completely insufficient.

Because level 4 and level 5 towns have already decomposed and absorbed many islands, on such islands, mountains that are more than three or four hundred meters high abound, and there are only three or four hundred meters high stargazing platforms, so it is impossible to observe the situation in the void at all times.

So once it becomes a level 4 or 5 island, it is imperative to build an obsidian observatory.

It was only at this time that they had the financial resources to build an obsidian observatory.

But now it's different, he has mastered the recipe for crystallizing clay, and with the combination of dark iron, he can even build a stargazing platform up to 800 meters high.

Such a stargazing platform, even if it is promoted to the city stage, can be used for a period of time, so the actual value of crystallized mud is even higher than that of obsidian.

But crystallized mud is only fired from the three most common materials, black crystal, clay, and gypsum, and once it is known to the outside world, the price of these three materials may immediately increase wildly.

Because the profit in this is too big, this is completely the price of selling a cabbage to Wuyi Mountain's big red robe.

He doesn't have many resources in his hands now, and he can't store a lot of these materials, so this matter can only be put aside for the time being.

Thinking about this information, a smile appeared on the corner of Xiao Han's mouth.

The first time the technology tree bore fruit, it brought him such a big surprise, and the value contained in the crystallized mud could hardly be expressed in numbers.

At this point, he was eager to make the other fruits of the tech tree ripen quickly.

Coming to the warehouse, Xiao Han threw all the last seventy or eighty corpses into the storage space of the technology tree.

After this period of growth, its height has increased to fifty centimeters, and it bears a lot of fruit, one or two thousand.

Xiao Han thought that they would soon ripen, and he could also obtain the knowledge contained in the technological fruit.

But until now, these fruits are still hanging on them, and they have no intention of ripening.

In this regard, Xiao Han was helpless, if this last batch of corpses still couldn't ripen these fruits, he would have to think of some other ways to get the corpses of some scientific and technological talents.

"Hey, there's a fruit falling!"

At this moment, Xiao Han saw that many fruits began to turn yellow, and then they fell to the ground "crackling".

"Haha, get rich!"

Seeing this scene, Xiao Han didn't hesitate, and skillfully pointed his fingers at the science and technology fruits that had fallen to the ground.

And all of these technologies flew back to the tech tree because of his touch.

As for what kind of technology was bred in the science and technology fruit, Xiao Han didn't rush to see it, his fingers fell to the science and technology fruit on the ground one by one.

After all the technology fruits are back on the technology tree, they will be checked one by one.

"Level 2 House Building Atlas!"

"Level 3 Farmland Cultivation Handbook!"

"Mortal-level five-grade demon hunting bow to create a map!"

……

Constantly checking the technology fruit on the tree, although Xiao Han had expected it, he was still very disappointed.

In the past hour or so, he has checked two-thirds of the technology, and the technology that can be used is indeed there, but the actual use is not great, and it will not bring him any benefits.

There is no technology like crystallized mud.

"Hey, it looks like I'm thinking too much." Sighing depressedly, Xiao Han no longer had the excitement he had at the beginning, but the movements in his hands still did not stop.

As the technology fruit was constantly opened, the technology bred inside was also presented in front of him one by one.

"Hey, telescope!" Looking at the technology on the screen, Xiao Han snapped his fingers and immediately stopped.

Carefully watching the introduction of the telescope, the joy on his face became stronger and stronger.

During this time, browsing the information on the Great Forum of the Heavens, he had also seen many posts seeking to buy similar telescopes.

In those posts, there are very clear requirements for the clarity of the telescope and the viewing distance, but those requirements are not at the same level as the data on the scientific and technological results.

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