Einar was in his office reviewing some documents about the daily production of different products.


    He was surprised when the door opened and he could see little Daven "Dad, can Ie in?"


    Einar smiled and put the documents on the table as he stood to go to the door for his son.


    Daven was quite happy when his father carried him in his arms. "Of course you cane in. There is always time for the family.


    Tell me if there is anything I can help you with? "


    Daven nodded and hugged Einar''s neck. "I was reading the book on fluids and I remembered the toy that can be yed with air.


    So I decided to make one of those toys but when I turn it using a little air, it makes a strange sound..


    Why is that happening? "


    Einar smiled and sat on the couch while he sat his son on his leg "The air is a fluid so when it passes through the des of the pinwheel they produce sound..."


    At that moment, he was silent for a moment and thought about how he could create an emergency siren. His mistake was that he was thinking of very modernponents.


    But he forgot the simplest thing that was to be able to use air to produce sound. He only needed to use air and some slits.


    It was the same process that wind instruments such as flutes used to generate sound, only this time it would be used to create a siren that would sound on the same musical note.


    At that moment, he looked at his little son with a smile. "It is time for us to do a little experiment. You want to work with your father to create a machine to create sound.


    I think there is no better way to learn than by experimenting with what can make sound. "


    Daven nodded and looked cheerfully at his father.


    Einar then lowered his son and took him by the hand as they walked towards theboratory. When they arrived, they looked at Sia going through some probability tables.


    "If this variant is removed, then Kassia should be type O + blood while Helmi is A + blood.


    But then it is voluntary and there is another that they are O + they could donate blood safely.


    But possibly another is blood type O- because tests show that no one who received his blood showed any problems.


    We would have to do another test, but you need at least a week to get the blood back in your body.


    The way the blood works is interesting, to think that we used leeches to treat diseases, but it was simple idiocy. "


    Sia then turned around and could see Daven and Einar. "Wee guys, are you going to do any experiments?"


    Einar nodded and looked fondly at his son. "We are going to make an emergency siren using a lever, an alternator, and a small motor that will rotate a steel te with air vents.


    If we can sessfully create emergency sirens, they can be ced on all defense towers and in towns to prepare for a possible invasion. "


    Sia looked seriously at Einar. "Is there someone who is going to invade us?"


    Einar only smiled in a forced way. "I would like to say no, but since I have no proof, I have no doubts either.


    But as a wise man would say, it is better to be safe than sorry.


    That is why the sirens must be produced, because their sound will be so loud that it will allow us to prepare defenses in a short time.


    I will also begin to establish a detailed n of militias and weapons in each vige in order to safeguard the safety of all.


    Fortunately, we have expanded almost throughout the ind, but with what we have advanced, I think we can have a solid defense.


    Of course, if the enemynds on the ind, we can always use guerri tactics to fight them in the forest.


    But let''s stop talking about negative things. Better help me to bring an electric alternator, wood, saw, pine glue, hammer, copper wire and my tools for carving wood.


    I will show you how we can make a small motor to transfer electrical energy to mechanical energy. "


    Daven looked at his father curiously. "Why don''t we just use a crank directly to move the piece of wood?"


    Einar smiled. Why the piece needs to rotate at a high speed, with the electric alternator, we will only put the basic mechanical force.


    While the electrical energy and the motor will be in charge of making the piece of wood rotate.


    It is a way of saving the resource, although also if we can manufacture a battery we could store energy.


    Which we could use so that the siren could work without turning the crank, but that will be somewhatplicated. "


    After those words, Sia and Daven went to look for things while Einar drew on a piece of paper the n of the emergency siren prototype that he would build.


    When his son and Sia arrived, Einar used a yardstick to measure the wood while marking the areas he would cut with a pencil.


    After having the woodpletely marked, he began to cut it. When he finished, he handed it to Sia and Daven to glue it using Einar''s marks and pine resin glue.


    While they were doing that, Einar used some metal gears that he had and started making the simple motors for the gears to turn.


    It took him a few minutes to create the entire mechanism, then he ced a shaft that was joined with the piece of wood that would rotate.


    That piece of wood had 5 des on the sides, so it looked like a blender. This also inspired Einar, as he could create a blender using the same process to make the emergency siren.


    Perhaps the only difference would be that it must have been a part that could be separated so that it could be washed, although its strength would not be as powerful as to liquefy ice if it could liquefy a lot of things for food.


    So you cut down on material waste when preparing food, not to mention you could create some apple, milk, and sugar smoothies.


    When Sia and Daven finished creating the wooden parts, Einar began to arrange all the parts for the new mermaid.


    Which was a bit big, but that could be changed by just altering the shape of the electric alternator because, due to time, he did not want to create a special electric alternator for the prototype.


    Because it was a prototype, it did not have a protection on the top where the des would rotate so it asked Daven and Sia to move away.


    When Einar started turning the crank, the disk on top of the machine started to turn and, little by little, he increased the speed until it started to make a strange noise.


    Daven and Sia were shocked, but everyone in the imperial pce who heard the noise of the anti-aircraft sirens felt fear.


    Einar, to give the effect of the siren, stopped turning the crank for a few seconds and then turned it again.


    The sound caused the guards of the imperial pce to establish a protection zone, as they did not know what that noise was.


    Even Helmi thought for a moment of Ragnarok.