In such an era where everything relies on manpower, completing communication work is a very difficult task.

Their only way to deliver messages is to urge the fastest horse to run the farthest road.

As for things like sending messages via carrier pigeon, they have not yet appeared, nor is there any disposition related to pigeons for this purpose.

Or perhaps, although pigeons do exist at this moment, no one has thought to associate them with message delivery.

Precisely because of this, even if someone really discovers the situation here and wants to send a message out, it takes several days,

and this delay of several days is enough to complete certain tasks.

This is also the reason for the classic saying, "in the field, military orders may not be observed."

This saying really only applies to ancient times like now; applying it to the modern world or the 21st century makes it completely useless.

After all, the reason for this saying is because in ancient times, message delivery was extremely slow, while matters on the battlefield changed rapidly, so much so that just a few hours could change a significant battle situation.

If you wanted to convey the effectiveness of a battlefield to the Capital City, to reach the ears of the Emperor, it would take at least several days, and these several days are devastating for a rapidly changing battlefield.

It is precisely because of this that the classic saying "in the field, military orders may not be observed" emerged.

Because if he really waited for the Emperor’s response, this battle might be completely lost.

By the time the imperial order arrives, this army might already have been dispersed, right?

But if placed in the 21st century, with highly developed communication equipment, you could say a message could be spread in just a few seconds; with such speed and capability, saying "in the field, military orders may not be observed" seems to be deliberate.

And perhaps there are also some other ulterior motives, right?

Of course, these things are just an excuse. It’s possible that his inner thoughts are just like this, thinking about disobeying orders.

That’s right, this is the extensibility of the era.

We’re getting a bit off topic with this discussion, so let’s talk about the current situation with Lin Yi.

After clarifying all the tasks at hand, he took Leng Yu and returned directly to the Border Army Camp at Shanhaiguan.

However, when they arrived at the Border Army Camp at Shanhaiguan, they were indeed stunned.

At this moment, what was once an incredibly desolate camp has become exceptionally bustling and lively.

You could say, in places where you previously couldn’t encounter anyone even after walking far, it is now crowded with people.

Frankly speaking, wherever you go, there are people.

Wherever you go, there are soldiers wearing armor.

After all, the original capacity of this Border Army Camp was only about ten thousand people, and even running at full capacity, having twenty to thirty thousand people would fill it up completely.

But now?

Now, suddenly, one hundred thousand troops have surged in here.

Plus the previous troops and those from surrounding areas, a total of around twelve to thirteen thousand troops have gathered here.

In such a quantity placed in a pass that can only accommodate thirty thousand people, how can it not be crowded?

Fortunately, with Lin Yi’s strong methods, these people have no worries about food, drink, or shelter.

Food is supplied by nearby cities, and as for accommodations, they just cleared an area by cutting down trees to set up camp on the spot. This is also one of the essential elements of ancient military campaigns, which is setting up camp.

Moreover, for them, the sleeping area couldn’t be simpler.

As long as there is a place to shelter from the wind and rain in this scorching summer, and a place to keep away mosquitoes, that’s enough.

Of course, as for the way they repel mosquitoes?

This is quite ancient; modern mosquito nets definitely do not exist here now.

Lin Yi realized this and understood everyone’s hardship.

In this hot summer, the hardest thing at night is the mosquito bites, especially in these wild mountains—even with a hundred thousand people gathered here, these mosquitoes show no fear,

especially these mosquitoes, which attack soldiers uninterrupted throughout the night, causing them much distress.

However, for them, this is already customary, as no matter where they are, they can’t solve the mosquito problem.

Therefore, when Lin Yi arrived here, he noticed this issue, and his solution was naturally quite simple.

On the first day of his arrival, he ordered people to start searching for mugwort everywhere.

He then had them assemble a small team.

The team’s main task was to mash the mugwort and mix it with some mud and certain types of grass selected by Lin Yi. After completing this, they would roll it into long thin strips and coil them up.

It was precisely this act that led to the first mosquito coil being created in the country of Dayou.

You could say, this is the first time in human history that someone made mosquito coils. Lin Yi taught them how to do this.

Initially, people naturally didn’t know what this thing was for, nor understood why people were ordered to make such things by the Emperor.

Looking at this coiled thing like excrement, people had doubts in their hearts and couldn’t help but mutter to themselves, what is this thing?

Why would His Majesty want us to play with mud?

This thing looks less useful than excrement, and they had no idea what it was for.

Could it be that His Majesty wants us to use this to siege cities?

Could it be that His Majesty wants to disgust those people of Zhao Country with this?

Admittedly, these guys have quite the imagination, and for a while, everyone began speculating.

And the content of this speculation is somewhat laugh-inducing.

Of course, the biggest sentiment was confusion; they didn’t understand what this thing could actually do because it could be easily broken by hand, and arguing its usefulness as a projectile would be unrealistic.

However, when nighttime came, Lin Yi called the generals of each camp over and personally picked up the thing in front of them.

"Generals, I have named this thing a mosquito coil. Watch carefully how I use it."

As he spoke, Lin Yi took out a lighter, snapped it to ignite a flame, and lit that lump of substance with it, instantly setting it alight.

Not only that, after lighting it,

[To be continued....]

ps: How many brothers are still reading with us now? Youzi, why does it feel like I’m playing alone every day...