Heller speculated maliciously, and Leah treated her with kindness.

Indeed, with a clear conscience.

Different force fields, different choices, and different fates are bound to be different. This is a fact that cannot be changed, what Lia can and must do is to stand on her own position, strengthen her faith, and respond to all changes with no change.

......

"The reason why ships can float on the surface of the sea is not because they are made of wood. And a force that exists in nature is called buoyancy ......"

"Various factors of the magnitude of buoyancy...... When studying the relationship between buoyancy and depth, keep the volume of the object constant...... The results show that the amount of buoyancy experienced by an object in the liquid is related to the volume of the object immersed in the liquid and the density of the liquid. The greater the volume of the object immersed in the liquid, the greater the density of the liquid, the greater the buoyancy. ”

Under the flickering candlelight, Qin Song was still writing at his desk, sorting out the relatively clear and accurate knowledge he could remember, making it into a knowledge light ball, and putting it in the temple. Up to now, physics, chemistry, mathematics, etc., although the introductory knowledge is fragmentary, can basically form a self-consistent theoretical system.

The introduction and study of buoyancy is the focus at present. Because the key point in the next step is the city of Arabe, which is far overseas, and ships are indispensable.

Understanding buoyancy allows witches to better understand and develop new types of ships.

The huge dry dock, supervised by Veronica's father, was completed and had a simple structure, a large trench that could accommodate a three-masted sailboat, a dock door that could be opened and closed, and a pumping system made of Blackstone engines, which could achieve basic drainage functions.

So far, the former princess, the strongest and most spacious ship, has become the first modified test ship.

There are two targets for the modification, one of which is relatively simple is armor, which is the prototype of the steel battleship - the armored ship. With Alice's ability to manipulate metal, as well as the black iron raw materials left behind by the orcs, a pair of segmented armor tailored for the ship, which is basically assembled.

The heavy armor increased the weight of the ship, the draft increased significantly, and in the end all the redundant facilities in the cabin that could be removed had to be dismantled, fully serving the war effort.

In addition, the difficulty of modification is the power system.

In Qin Song's concept, the Blackstone engine is the best power source.

After several rounds of testing, the original scheme of blindly zooming in on the Blackstone engine was abolished in favor of another integrated engine solution - that is, twelve small Blackstone engines, through a gear unit, in a V-shaped position, and the power was transmitted on the same shaft, making the space more compact and the stability improved.

Even if one of the twelve engines fails, the engine will still work, and only some horsepower will be lost.

This is far less difficult than building a giant engine, and it is safe and stable.

This scheme is also known as the V12 Blackstone engine by Qin Song.

After the engine problem was solved, the energy supply unit was put on the agenda. In order to save manpower and material resources for cutting crystals, under the brains of Veronica, Alice and others, a very brain-opening device was designed - spherical crystal slots.

The reason why it is designed to be spherical, rather than a cube cuboid, is because of the crystal. These crystal clusters are actually pyramids, and they are not particularly uniform in size.

However, it has been observed that even if the size of the crystal clusters is different, their crystal structure is the same, that is, the angle between the edge and the edge is the same, and the vertex of the pyramid and the inner angle of the connected edge are constant.

This means that the pyramid forming the sphere is more space-saving and material-saving. Even if the size of the crystal clusters is different, the pyramids can fit together perfectly, except for the different lengths of the bare outside.

After many trial productions, a prototype of an energy supply device made of demonic metal with crystal grooves on the surface of the sphere was born. The spherical surface of this device is divided into left and right hemispheres, with six independent areas in each hemisphere, corresponding to the twelve engines of the Blackstone V12, which is extremely convenient to use, just select a crystal cluster of small size, align it with the slot and put it into it. And when the magic of the crystal cluster in that area is exhausted, just pull it out and replace it with a new crystal cluster.

Alice's manipulation of metal, coupled with Veronica's miraculous and precise craftsmanship, made the device very smoothly manufactured, and the final product resembled flower petals, and when filled with crystal clusters, it was even more gorgeous, like a blooming flower, so it was named - the flower of energy.

The Blackstone V12 engine + energy flower form a perfectly coordinated power plant.

Although they are only prototypes and have a certain failure rate, as long as they are continuously improved, they will gradually become perfect and become a mature and reliable power system.

Just as I was rejoicing, another conundrum arose.

Propeller drives.

Gearing is not a problem.

The problem lies in the sealing of the propeller drive shaft.

Suspended under the sea surface, the propeller outside the hull, there must be a certain gap in the transmission connection, under the action of water pressure, water seepage is unavoidable.

At least not for now.

Because Qin Song didn't know anything about the waterproof structure of the propeller......

Especially without the key product of rubber, there is no way to talk about rubber seals.

Oil seal, mechanical seal or water seal?

The larger the propeller, the worse the water seepage problem. In the absence of a stable waterproof structure, seawater seeps into the system and corrosives metal structures such as gears and shafts.

If you use it for a short time, you may not be able to show it. But if you sail for a long time, it is a huge hidden danger.

No matter how strong the power system is, the drive device is paralyzed, and there is only one ending. In the case of dismantling the sails, if the ship lies on its stomach, it becomes a dead ship.

If the waterproof problem is not solved, the ironclad expedition is all a dream.

This is the reality of Chiguoguo.

Qin Song's hair is worried, oh yes, by the way, there is no hair.

After completing the small chapter on buoyancy knowledge, Qin Song picked up the fourth version of the propeller drive device designed by Alice, using a multi-layer hinge device, but it was still too idealistic and full of hidden dangers.

However, the specific situation will be determined by another day's experiment.

Then, Qin Song took out a list from the depths of the drawer, with the names of the three girls written on it. Since the girls of the right age were gathered to live and study in unison, through the Eye of Insight, only one witch seedling was discovered.

Joe Walter, a two-star witch.

A shy little girl with long aqua blue hair, only eleven years old, her father was a fisherman in the original Daotan Town, specializing in trout, pike, etc. for the lord, and later the lord hung up and was exiled to the Black Stone Collar as a refugee.

His father, who was honest and good at fishing, is now back to his old profession, fishing in the River Ness, supplying the catch.

Four-star and five-star witches are very rare in themselves, and Qin Song is not extravagant. Nearly sixty girls were examined, and only one girl with witch potential was selected, and the probability was a bit too low.

For Qin Song now, the interstellar nature of witches is no longer the primary issue, and the key is whether they have potential or not.

It's just that my energy is limited now, and I can't wait to use it at night as a daytime, so I have little time to guide myself in my dreams. The question of conversion is left to the other witches, and in the course of life and study, they are made to have natural beliefs.

Calculating the time, the juvenile study class has been open for more than half a month. Veronica is their guide, compiling several basic books and having a regular class schedule every day. In life, Blackstone is fully responsible for eating and lodging.

In their spare time, because the girls are generally serious and skillful, there will be some chores such as processing small metal parts, making maltose, picking vegetables and fruits, etc., which will be given to them to feel in practice, and a small amount of wages will be taken with them.

In addition, there is also a studious award, and some girls who excel in their studies will receive various rewards to further increase their motivation.

As it turned out, the reward had a miraculous effect on these children, who generally came from poor families, and a small bag of salt, a small bag of finely ground flour, a few pieces of maltose, etc., made them flock to it and enthusiastic.

Children, simple and simple, are the easiest to guide and easy to build trust.