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There are a total of five things that the third master handed over to Lu Donglai.

The first four have a fixed color, while the fifth one is very mottled, Lu Donglai didn't expect that there are actually four metal substances in the ore of the cultivation realm, and this fifth kind either has not reached its melting point according to the current temperature, or he is indeed a stone.

"Thank you, Third Master, the disciple will definitely give you a surprise when the time comes. ”

Throwing away the stone and taking the remaining four metallic substances, Lu Donglai quickly returned to his room.

Fang Qinghal and Lu regretted that they couldn't tell what these objects called 'metal' did, but Lu Donglai was quite clear.

Copper, a metal with a simple color and light weight, has a fairly good conductivity, but it is prone to oxidation.

As for the other three metals, they are 'silver', 'zinc' and 'steel'.

Lu Donglai didn't expect that there were so many of these metals in the cultivation realm, and there were minerals left over from casually refining weapons.

Probably because there is no technology in the world to extract a certain metal, or they think that these metals are useless, so they don't bother to pay attention to them.

Among the four metals, Lu Donglai chose 'silver' as the conductivity.

Silver is a material that is malleable and conductive, and although it can't be made into something like 'silk', it doesn't matter if it's a little thicker and not so uniform.

I don't know if there is such a thing as a magnet in this cultivation realm.

Thinking of this, Lu Donglai directly asked Fang Qinghal on the side, if you want to say who knows these things best, just find Fang Qinghal.

When Fang Qingzhen heard this, he said that he had not seen it, and immediately said, "Senior Brother Lu, if you need it, I will go and inquire." ”

Lu Donglai waved his hand, "It's okay, it's okay, I'll just talk about it casually." ”

If you have magnets, it will be easier to do, if you don't...... Of course, there is not much difference.

The reason why you need magnets in your own world is because you need to complete a battery and an electric energy engine, but in the cultivation realm, although there are no such things that already exist, there is a magic circle...... Circles can provide an endless supply of electricity.

So Lu Donglai didn't care so much.

As for the magic circle that can provide electric energy, after all, it doesn't need electricity like lightning, just provide some simple electric energy, and you don't need to electrocute people, this is not a magic circle used to kill people after all.

This kind of thing, just find someone who understands the circle to get one.

And this matter requires Fang Qinghal to find someone to make it.

When Lu Donglai explained the general requirements to Fang Qinghal, Fang Qinghal said that he understood, "I'll do it." ”

The rest of the work is quite simple, connect the silver to the ends of the carbon filament, put it in a glass bottle, and use a spell to extract the air from it, and then seal it.

That's it with a simple light bulb.

An anti-counterfeiting mark, Lu Donglai is not afraid that this technology will be stolen, and others may not know how to get rid of the oxygen in the glass bottle, because those monks have not studied physics and do not understand the composition of various gases in the air, even if they can make exactly the same or even more perfect bulb, but as long as the air inside is not extracted, it is also a failed bulb.

If the carbon filament is burned in the air, it is easy to oxidize, which in turn reduces the life of the carbon filament.

And if it's in a vacuum...... The life of the carbon filament will be correspondingly much longer.

In the evening, Fang Qinghal had already returned with a simple power generation array.

"Senior Brother Lu, according to your instructions, as long as you put a spirit stone in it, it will generate electricity on its own. ”

Lu Donglai nodded, took out a lower grade spirit stone from his body, and after some attempts, Fang Qingzhen's eyes became brighter and brighter, this ...... There was a light in the glass bottle, and it was so bright.

Lu Donglai was satisfied, the electric light was completed, and it seemed to be quite successful.

Fang Qingzhen still looked incredulous, "Senior Brother Lu, I used to know that luminous stones could emit light, but now I have discovered that there are more things that can emit light in this world, it's incredible, those things are things that others in the cultivation realm don't need, Senior Brother Lu, you are simply too powerful." ”

Being so touted by his own fans, Lu Donglai looks a little fluttering, this feeling is really refreshing.

But the business must be explained.

Lu Dong looked at the glowing electric lamp, and then said, "Halal sister, when you sell the electric lamp, remember, handle it gently, this thing is a fragile item, as long as the thing is taken away on the same day, once damaged, it will not be returned, of course, in order to check whether the lamp is intact, you can use each bulb before selling, in addition, the service life of this thing is 1~2 years, which must also be clearly explained." ”

"I see. Fang Qingzhen nodded.

"In addition, the intensity of the light depends on the power of the 'power array', in addition, the power of the 'power array' is proportional to the 'service life of the bulb', that is to say, the greater the power of the 'power array', the shorter the service life of the bulb, and now the light bulb on the ground, the luminosity is about 25w, and you can use this as a reference to fluctuate up and down in the future light comparison. ”

"Good. Fang Qinghal continued to nod.

"Am I talking too much?" Lu Donglai wondered.

Fang Qingzhen hurriedly shook his head and said, "No, no." ”

"That's good," Lu Donglai continued, "In addition, there is nothing if these materials are leaked out, but there is one thing that must be done by yourself, which is the essence of the entire light bulb, and must not be known to others." ”

Fang Qingzhen's head kept nodding like a chicken pecking rice, "Hmm, hmm." ”

Subsequently, Lu Donglai said about the extraction of air from the glass bottle, and Fang Qingzhen was puzzled, "What is a vacuum, is there any difference between doing it like this and not doing it?"

The strong woman in front of her is good in everything, but she is too eager to learn.

Lu Donglai spent a long time popularizing several gases contained in the air to the other party, and when he left, Fang Qingzhen was ignorant, obviously this news had to be digested for a long time.

"I'll keep this bulb for now, and I'll send me a few more tomorrow, and you'll take care of the rest. ”

Lu Donglai will be very easy in the next few days, but he knows that Fang Qingzhen is afraid that he will start a lot of work again.

At night, Lu regretted holding Lu Donglai's hand again, "Brother Donglai, can you continue to tell me stories tonight?"

Lu Donglai lay on the bed, looked at Lu Donglai, who was carved like a porcelain doll beside him, and said with a smile, "Then my brother will tell you a story about an ugly duckling tonight." ”

"Hmm. ”

"...... a long, long time ago" (To be continued.) )