Chapter 741: The Art of Sound Transmission……
Translator: TransN Editor: TransN
...
Roland wiped the fine sweat beads from Anna's forehead and held her in his arms.
In the dim light, he could still see the attractive blush on her face.
Roland had the feeling that Anna had become more active in this regard since the last time they talked about the Dream World. She also tried to learn some new tricks—though her progress was much slower than her learning from books. Anna's clumsy and serious manner gave him an entirely new experience. His visual enjoyment far surpassed the sensory experience and he could not help but feel a sense of superiority as an old hand.
Of course, they would not miss the storytelling session after their time of joy.
As he was indulging in Anna's fragrance, Roland started to narrate in detail the news brought by the Taquila Witches as well as his speculation about the Battle of Divine Will.
"Although we've already known that where we live is no larger than a corner of the mainland, I didn't expect that there were actually completely different civilizations scattered beneath the mountains... this world is really full of unknowns!" Anna sighed and said, "Perhaps one day, we can also set foot on that faraway land to see what kind of secrets are hidden in that world across the sea."
"I promise that day will come," Roland answered with a smile.
Even if they could not travel by sea, they could still fly over it—any land that could be seen through the telescope would not be too far away. As long as they had the internal combustion engine, the large airship could come into play.
"But does God really exist? He left relics causing us to fight against one another... maybe he is now looking at us from somewhere."
"Are you afraid?" Roland could not resist holding her even closer.
"No, I want to thank him."
"What for?" Roland was a little surprised.
"For he sent you to me." Anna looked up and whispered.
Roland saw the rippling blue lake in her eyes—that was her unconcealed emotions.
He felt a warm current surging in his heart.
"I'll always be with you."
"But you can't stay with me all the time."
"I..."
Anna covered his mouth before he could finish speaking.
"You're the king and also the future commander of the army that will combat the Army of Demons. How could you stay forever in Neverwinter? I can't possess you entirely just for my personal desire. The soldiers who fight in the front line need to see your presence and your subjects in the other cities want you to be with them," she said softly, "Roland, I'm already very content that I can listen to your stories like this."
Roland was silent for a moment. "You're right. But wherever I am in the future, you will always be able to hear my stories... I promise you this."
Anna blinked, as if she had heard the meaning behind his words. "Without the Sigil of Listening?"
"Exactly." He nodded.
How could they speak out their words of love if they had to communicate through the Sigil of Listening?
"What are you going to do?"
"I'll let you know tomorrow." Roland rolled over and lay on top of Anna, then kissed her neck... and slipped all the way from her neck to the clavicle, leaving a shallow mark on her fine, tight skin. "But, now it's my turn."
Once again, they became one, and their sweet breathing sounds rising and falling for a long time before fading away.
…
The next day after breakfast, the invigorated Roland walked into the backyard of North Slope Mountain with Anna.
"Good morning, Your Majesty." Lucia, who had arrived even earlier, put her work aside and bowed before him.
"Good morning, Your Majesty! Good morning, Sister Anna! Sister Nightingale!" Ring followed the actions of her sister, and started to bow and cry out cheerfully.
Roland waved his hand with a smile, indicating that they did not have to be too formal. Then he walked to the workbench and pulled out a piece of white paper on which he started to draw a design. He intended to carry out the promise he had made last night to Anna before the Taquila survivors moved to the Western Region—a communication tool that he could use to speak to Anna at any time without magic.
That would be the wire telephone.
The principle of the telephone was very simple and that was the most basic application of electromagnetic induction: the sound wave would vibrate the metal reed in the voice tube causing the change of the magnetic flux formed in the magnetic field, and finally a fluctuant induced current would be generated. While the earpiece, on the contrary, would use the magnetic force generated by the electromagnetic coil to vibrate the membrane and reduce the current into voice.
In other words, it was fundamentally the same as a generator or an electric motor, except that the latter turned the vibration into a rotation and had a much larger power.
As soon as he articulated his idea and design, Anna immediately understood how this unprecedented calling tool worked.
"Let me get Mystery Moon and Soraya!" Her eyes shone with excitement.
"Electric current... exchange with voice?" After hearing what Roland had said, Nightingale still had a vacant look on her face, and when she turned to see if Lucia had understood, she found Lucia was also pondering.
"Electricity and magnetism originate from each other, and the magnetism turns into power... I see."
Even the little girl Ring also showed off her knowledge. "Sister, are you talking about something in the second chapter of 'Elementary Physics'?"
All of these reactions suddenly frustrated Nightingale. She gloomily picked up a dried fish and walked into the Mist.
Roland could not hold back his laughter at this scene. He knew that although the principle was simple, it was not that easy to make a functional phone, and the problem lay in the signal transmission.
The electrical signal would abate.
That was the reason why the phone was not widely used in the early stage after it was invented—once the distance between the callers was too long, it was hard for one side to hear exactly what the other side was saying. The phone was not widely used until the electron tube that could amplify the signal was invented.
Roland was not very good at electricity, so he barely wrote about it in his books. Even now that he had the help of the Dream World, he still found it quite problematic to make an electron tube.
Since he did not intend to amplify the signal, there was only one way to do it—by reducing the attenuation.
For example, increase the size of the wire and reduce the loss of the signal in the route.
The former was very simple to achieve. The required copper wire could be accurately processed by Anna's Blackfire. According to the knowledge he had acquired from his Dream World, a 4 mm diameter wire could be used to maintain a 50 or 60 km communication without a repeater, while the general telephone connecting wire was only 0.4 to 0.6 mm in diameter. Although it was somewhat wasteful to use the thick wire, it could effectively avoid the trouble of having to make a signal amplifier.
The latter could be achieved through coaxial-cable—the so-called coaxial-cable was made by wrapping the wire with a layer of metal mesh which would be sandwiched by the two wires that were coated with insulating materials and turned into a Faraday cage so as to minimize the divergence of the electrical signal. Before the telephone came into widespread use, the technology of wrapping the metal layer was not mature yet, so at that time, people used the loading coil, which meant overlapping the wire with a spirally wound coil casing to reduce the signal loss. But Roland did not need to follow this rule since he had Anna's processing skill and Soraya's special coating that could complete it in one step.