Leaving Poltava, Empress Elizabeth and Crown Prince Peter and their entourage traveled south along the Dnieper River to Petrovsk, on the border of the Ukrainian steppes, which is also an important commercial port.

Since the Russian Empire had only one port on the Black Sea coast, the rest of the country could only be connected to the Black Sea by land and water, and Petrovsk was a well-located inland port that could quickly transport troops south from the north in times of war.

"If Crimean Tatar can be taken, it will definitely become a transit point for agricultural trade in the Ukrainian region"

Peter stood on the pier by the Dnieper and looked out over the wide river.

Historically, after Catherine the Great defeated the Ottomans and took the entire Crimea, the Slavic city of Catherine was built here as a regional agricultural trade center.

"Marshal, I want to ask a question"

Peter saw galleys carrying soldiers leaving the dock and heading south down the river.

"Your Highness, but it doesn't hurt to say it"

Marshal Apleksin Jr. looked grim.

"If the Tatars invade here, how long will it take for the news to reach St. Petersburg?"

"Well, it should take about ten days, and if it's winter, it's estimated to be about fifteen days."

"Why does it take so long? I see that there is a beacon or something, so it should be very fast to deliver the message, right? ”

"The beacon can only be transmitted to Kyiv, and if the beacon is also used further north from Kyiv, it will be impossible to distinguish whether it is an accident on the Polish border or an accident in the Crimea"

"Huh? Can it still be like this? ”

Peter asked, surprised.

"Yes, Your Highness, so important news still needs to be delivered quickly"

"I have an idea to deliver multiple messages with different meanings on the basis of the beacon."

"Oh? Your Highness, please say"

The field marshal seems to have taken some interest.

"I want to ask first, does the marshal know what the Dutch windmills look like?"

"Well, although I haven't seen it with my own eyes, I have seen windmills in paintings, but there are basically no windmills in my country because of the freezing ice in the north. May I ask if His Highness's thoughts are related to windmills? ”

"Yes, if I hadn't traveled to the Netherlands as a young man, I wouldn't have thought of this method."

Peter stole a glance at Empress Elizabeth, who was talking to Catherine not far away.

"May I ask the marshal, have you already had a new idea after listening to what I just said?"

"Well... The windmill is related to the wind, but whether the fan turns left or right, it can only express two meanings, and once the fan rotates, the recognition of the direction of rotation is not high, and it is not easy to read the message quickly in the case of low visibility."

"I said Marshal, although your professionalism cannot be questioned, I have learned your rigidity many times."

"Hehe, Your Highness, please bear with me..."

Marshal Apleksin Jr. had a little on his face.

"Then I ask you, who said you have to use the same fan blades as the windmill? Won't you be flexible? Grab a pen and paper! ”

Peter drew a sketch on the spot on paper.

In the picture, two windmill blades of the same size are mounted on a balance beam.

Then, Peter also drew several combinations of symbols such as ×∧, ×∨, ∧×, and ∧∧ next to the sketch.

"Wouldn't that be able to express a lot of different meanings?"

Peter shook his hand and shoved the drawn paper into the field marshal's hand.

"This... Amazing idea indeed... In this way, there is really a lot more in the expression of the message"

Peter noticed that the marshal's hands trembled a little.

"But... But in the daytime, it's not easy to distinguish between a fork and a hook, right? ”

"It's up to the marshal to study how to implement this, I'm not very professional in design, but I suddenly have an idea, you can also simplify and improve. In short, I think it's possible to deliver more than two kinds of messages quickly."

"I see what Your Highness means, if this new type of communication tower is spread all over the border, it will be possible to reach St. Petersburg in almost a day."

"By the way, I think that even if you can only express the meaning of fork and hook at a time, if you make each letter into a combination of fork hook or hook hook, you can still send a piece of text, and the marshal must not be bound by the invisible wall in his mind."

As the sun set, Peter smiled kindly.

"Well, I see, Your Highness's thoughts did inspire me"

Damn, this is not nonsense! Lao Tzu has even taught you the Morse code of later generations, if you don't open your mind again, I'm really going crazy, okay!

"Marshal, what were you talking about?"

By this time, Empress Elizabeth had already walked over.

"Back to Your Majesty, His Royal Highness the Crown Prince has just made a very useful suggestion for..."

"Well, let's get back to that, Alexander. Ivanovic found out something about the previous attack on the royal convoy, so we are now going back to Poltava."

"Your Majesty, will you go to Zaporozhye to inspect later?"

"This is to be determined, if the Ottomans continue to provoke without interest, I will accompany you to the end!"

Empress Elizabeth said with a resolute look in her eyes.