The Grey Keep, Winterless.

Since the news of the enthronement ceremony was announced, Roland handed over all the preparations to Barov, and the latter also seemed to be very attentive, not only busy every day, but also asked people to invite the ceremonial official of the old royal capital, Ms. Blanche, to Wudong, obviously unwilling to make a mistake.

As for himself, apart from occasionally checking on the filming progress of the Shadow, the rest of the time was devoted to finalizing the internal combustion engine.

Due to the existence of certain errors in the weights and measures of the two worlds, the prototype needs to pass the stability test, and the oil quality of the fractionation is uneven, and the design redundancy is also a necessary consideration.

Manufacturing-experiment-scrapping-improvement-repeating, Roland seems to have returned to the campus era, running between the castle and the mountains behind the north slope every day, living a busy and fulfilling research life, and those knowledge that has not been touched for a long time have become vivid again in this half month.

Of course, there was no Anna with me at that time.

What's even more beautiful is that she is no less passionate about new things than she is herself.

Whenever she saw her focus on assembling the delicate parts, and touching the beads of sweat from the tip of her nose to leave a string of mimeographs, Roland couldn't help but sigh - her desire to create and learn seemed to be innate, as hot and pure as her flame.

This inner spirit is beyond the scope of what can be described by appearance, and it never gets tired of seeing it at any time.

Anna's smile almost could be described as a bloom when a decisive step was made—he even felt that the joy of creation was far more for her than being queen.

She has never hidden her thoughts - as long as the two can stay together, she doesn't care too much about the fame.

Of course, Roland also knows that sometimes the name is not to show the other party, but to show everyone.

As long as humans are social animals, this cannot be avoided.

After marking a series of revised dimensions on the drawing, he put down the quill pen and rubbed his somewhat sour neck.

If nothing else, it's likely that these designs will be finalized – after all, the last batch of prototypes has been running stably for several days, and the cumulative working time is enough to meet the current needs.

As a second-generation power source, the principle of the internal combustion engine is not complicated, and it can be regarded as an evolutionary version of the steam engine. The first generation of power sources were driven by steam to push the pistons, no matter how cleverly designed, it could not avoid the energy loss caused by steam delivery, so people naturally thought that putting this power directly into the cylinder would inevitably greatly improve the work efficiency, and the internal combustion engine was born.

Oil is mixed with air and injected into the cylinder, causing it to burn violently, and the expanded air flow will propel the piston while sucking new fuel into the cylinder – it sounds simple, but it's a huge undertaking to achieve. For example, the steam engine has low sealing requirements, and the gap between the piston and the cylinder block in the early products can even be stuffed with a finger, and felt and linen can be used to plug the seams, but it is obviously not feasible to replace it with an internal combustion engine.

It is not powered from the outside like a steam engine, and each cycle of the piston needs to be completed by itself, so if the seal is not tight, it will cause the cylinder to stop due to lack of fire.

In other words, this simple principle can only be turned into reality when the level of materials and processing technology reaches a certain level. It is for this reason that the first internal combustion engine in history was actually created decades later than the electric motor.

The first-generation internal combustion engine concept designed by Roland was designed in two directions, one was an in-line cylinder and the other was a cyclical cylinder. The former is stupid, black and coarse, made of cast iron, how stable and how to come, and strive to be put into the factory for large-scale production. The latter, also known as the star engine, can be made very small due to its short and compact crankshaft, making it ideal for spacecraft use. It is much more refined than the former, and the material is made of aluminum, which can only be processed by Anna for the time being.

The reason why Roland dared to develop two sets of products in the research and development stage is nothing more than standing on the shoulders of its predecessors. For these two tried-and-true titles, there is a lot of information to be found in the dream world, and this time the starting point is much higher than the steam engine, which has already undergone four generations.

Coupled with the information revealed by the high-level devil, he also had to speed up his pace.

Ground defense alone makes it difficult to survive a massive threat from the skies, and this expedition has proven it.

If this happens, for the first time, humanity will have the ability to compete with the enemy in the air.

"Your Majesty, don't move. ”

The nightingale spoke suddenly.

Roland paused immediately, and at the same time his eyes looked back.

Is there a ...... Enemy?

Then he saw the nightingale approach, reached out and touched the top of his head, and then, in a slight pain, she placed a strand of hair in front of him.

"Uh, this is white hair?" Roland laughed and cried for a moment.

Although the gray hair itself is very light in color, these strands do have a bit of a noticeable whiteness, and they almost lose their luster from the roots.

"And what," the nightingale groped for a while, "haven't you been resting too little lately?"

"Is there one?"

"You used to sleep lazily in the winter, but lately you have to wake up earlier than me, and you have to enter the dream world at night, so you can't really fall asleep, right?" she gushed, "Yawning from time to time is a proof of fatigue, and you have gray hair before you are thirty, how can you go on like this." ”

Looking at the other party's serious admonition, Roland's heart couldn't help but feel a lot lighter, and even the fatigue of work faded a little, she really didn't suffer too much, it seems that the agreement did play a vital role.

"Don't worry, it's not even the limit, I've already experienced it. ”

"......" Nightingale looked skeptical, but it was clear that she could tell that it was not a lie.

Because he really wasn't lying, "Generally speaking, there will be a long period of palpitations for a long time, as if the chest is particularly empty, and then you will feel that you can't lift your energy, so you should be careful." If you react strongly, you'll cough incessantly, and even bleed all the blood—cough, cough, cough—"

In the middle of speaking, he suddenly coughed violently.

"Hey, are you alright?" Nightingale suddenly looked nervous and patted him on the back, "Do you need me to call Nanawa?"

Roland took a deep breath, "No...... It's okay, I just choked on my saliva. ”

"Really?"

"Don't worry, I-"

He turned his head, froze for a moment—they were almost close to each other, and they both held their breath involuntarily as they looked at each other.

"Your Majesty," just then, the office door was pushed open, and Wendy walked in, "I have something to ...... Hmm, what are you doing?"

"Me?" Roland blinked, only to find that there was no one in front of him, and he maintained a half-leaning posture, even if he knew it needless to say, it must have looked rather strange.

"Your Majesty is practicing gymnastics," Nightingale was lying on the coffee table at some point, chewing dried fish with a very leisurely appearance, "It's easy to get sore after sitting for a long time, so he can try the effect himself." ”

"I see," Wendy said thoughtfully, "is this the gymnastics you mentioned earlier......, which you are going to promote in the academy?" Does it really work like this?"

"Well, it's okay," Roland regained his posture in embarrassment, for some reason, he always felt that the innocent-looking nightingale was trying to hold back a laugh, "By the way, what are you trying to say?"

"That's right, Your Majesty," Wendy said as she flipped through the notebook in her hand, "according to the records of the previous year, today should be Lightning's coming of age. ”