Before going to Haizhou, Li Yuanjing had to solve the problem of the steam engine first, there is no doubt about this.

Although he knew that the development of maritime history had gone through the era of oars, sails, steam, and internal combustion engines, Li Yuanjing directly ignored the era of sails.

Why waste so much precious time when you could have a steam engine?

However, the age of steam is divided into two eras, the paddle era and the propeller age.

The paddle wheel has the advantages of the paddle wheel, for example, you don't have to worry too much about the waterproofing problem, but the disadvantages are also obvious, the ability to resist wind and waves is almost zero, and if this structure encounters wind and waves at sea, it will be completely blind, and the performance is even worse than the oar.

And it is not as good as the propeller in terms of power, but the biggest difficulty of the propeller is waterproofing, as the only part that protrudes from the hull, it is impossible to achieve complete waterproofing.

Li Yuanjing did not plan to consider the precision parts involved in it for the time being, and he would not be able to do so without that condition.

But the basic principle is still known, for example, through the size of the bearing array to play a certain effect, and then fill it with sealing oil to strengthen the effect, of course, for the sake of insurance, there are also at the same time on the air seal, which is equivalent to a triple guarantee.

If you can do this, you can basically guarantee that there will be no water seepage.

Ideas Li Yuanjing is naturally not lacking, but what is lacking is materials, he can't even make a sealing ring now, to be more precise, there is not even rubber, what to use to make a sealing ring?

"What is certain is that fig resin does work, but the problem is also obvious!" Yu Guang pointed to the steam engine that was leaking and said: "A sealing ring can be used for up to five days, and the short time is just half a day, these without exception will be deformed first, and then start to leak, and when it is removed, it will be like this!" ”

Li Yuanjing focused on the several seals that were removed, the shape was indeed a bit miserable, in addition to the deformation caused by high-speed friction and heat, there was also the deformation caused by disassembly, but the latter can be ignored.

Don't think about it, Li Yuanjing also knows what the problem is, in addition to the fact that the fig resin itself is not the best material, the biggest problem is that there is no stabilizer, although after some special processing methods, or adding some other raw materials will increase its durability, but without stabilizers, this improvement is limited.

It is not a trivial matter to replace the sealing ring of the steam engine once, especially in the working environment of the ship, is it difficult to replace the sealing ring after working for three or four days? It was necessary to remove some of the things and install them, which was faster and took about two hours.

"Try adding some paraffin, and add a thin layer of steel wire mesh in the middle!" Li Yuanjing happened to know a stabilizer, and he didn't know if it could work, anyway, he had seen them add paraffin wax to rubber when he was doing odd jobs in a small workshop before.

As for the steel mesh, one is a reference to the design of the tire, and the other is because of the thickness of the sealing ring.

On the other hand, the thickness of a sealing ring is as thick as two fingers side by side, and it is not a big problem to add a layer in the middle, and it should be replaced if it is not worn out in that position.

Li Yuanjing's suggestion is not a problem for the workshop, although the paraffin wax is not here, but Datang is not short of this thing, the only thing that needs to be studied is to add the proportion, the steel wire is simpler, and you don't even need to go to the iron smelting workshop, you can build it by picking up some leftovers.

After more than half a month, Li Yuanjing finally received good news, but also received bad news.

The good news is that after adding paraffin, the stability of the sealing ring is higher, they have been testing for eight days in a row, the steam engine has not leaked, and it was found that there is some wear and tear after disassembly, but it is not serious in comparison, according to the experience of Yu Guang and others, this kind of sealing ring can probably be guaranteed to be used continuously for about a month.

Considering that the ship is not constantly used, at least at night is to rest, so in actual use, there is a high probability of a month and a half to two months to replace.

However, the bad news is that there is no fig resin left, and the few fig trees of Cai Xu Kun are already crumbling, and they have long been pumped like people have been drained of blood, and the newly planted ones will not be used for at least a year, and even next year, they can only be extracted in small amounts.

Before leaving, Li Yuanjing entered the palace, and there were some things that he had to tell Li Shimin in advance to avoid accidents.

"I heard you had people destroy their crops and plant a kind of fruit tree?" As soon as the two brothers met, Li Shimin asked directly, the fig tree he knew, he had even eaten figs, which were very sweet and delicious, but there were not many of them.

"Brother Chen's coming here today is actually for this matter, Brother Chen hopes that Brother Huang can send a forbidden army to protect that forest, and send special personnel to take care of it!" Li Yuanjing didn't go around either.

"What's the name?" Li Shimin immediately realized that those fruit trees were not just fruits.

"Brother Huang should have heard of the steam engine, right?"

"That thing called a steam engine?" Li Shimin couldn't help but grinned pungently, this means that he didn't spend the court's money, otherwise Li Shimin would have to go berserk Li Yuanjing, a group of people worked on it for two years, wasting a lot of materials, but when he asked, he replied that he didn't have any use except for seeing the heat of the white flowers.

"Yes, after the fig resin is refined, it can be used to make sealing rings, and now the steam engine has solved the problem of air leakage, and next, the younger brother plans to build a new ship to test it, if it is feasible, it will be ...... for Datang" Li Yuanjing thought about it, scratched his head again, and then came up with a metaphor that can make people understand and see the gap.

"For example, the current Datang is a five-year-old child, so once the steam engine technology matures, Datang will directly become a twenty-year-old young man!"

Listening to Li Yuanjing's description, Li Shimin was a little unconvinced, if Datang was a five-year-old child, then what were the little brothers around? A year old? Or a two-year-old?

Can a steam engine bring such a big change to Datang? No matter what others say, Li Shimin doesn't believe it anyway.

Looking at Li Shimin's expression, Li Yuanjing probably knew that Li Shimin didn't take it to heart, but that forest was really important, and not only that forest, but also continued to expand the planting, one Huangzhuang was far from enough, which required Li Shimin to call other land, so this explanation had to be given.

"Whether the royal brother believes it or not, it is nothing more than a waste of manpower and a waste of some land, but what if it succeeds? Far from it, if it is used on a boat, starting from Haizhou, it will take a little more than a day to reach Tamna, and if it is used on an excavator, the efficiency will be increased by more than ten times. ”