Note: see in the articles VENT007E and VENT002E where everything started and why Tubald wants revenge.


Again the scene repeated itself: the preboste’s entourage of Lemon city left pompously the laboratory of Professor Ventura at the Technical School. For readers wishing to know how the mayor came to be called “preboste”, we suggest reading the previous adventures. Also in them, the reasons why Bart and Bert looked worried, half hidden and not approaching much, waiting for the entourage to move away!


- We can go now! The professor is neither handcuffed nor wearing a straitjacket! - Bart noted as he walked towards the teacher. He then asked as he approached the professor: Is Everything all right, Professor?


- Yes! Don’t worry! I was forgiven once more...


- And we have more work, right? - Bart interrupted, asking.


- Exactly, and once again you will help me! The professor said this signaling for the two of them to come in. He would explain what the "preboste" wanted!


Accommodated in the armchairs of the old lab, Bart and Bert were once again ready to listen to the professor's explanations and help him on a new project:


- You know, our town has all its economy based on the production of lemons from the many farms that surround it. Therefore, it is known, in the whole country, as the "capital of the lemon".


Bart interrupted:


- Yes, but that's also why everyone laughs at us, saying that whoever is born in Lemon city has the "sour face"!


No one laughed, and the professor continued:


- Well, our city is 200 years old in a few days, and the mayor wants to have something special for the anniversary. That's why he came to me!


- There's a bomb! - commented Bert. The professor did not care about this and went ahead with his explanations:


- His idea has no way of going wrong! He wants us to install a "lemonade fountain" in our square!


"Lemonade fountain?"


Bart and Bert looked at each other, amazed at the preboste’s idea and did not see how it would have something to do with the professor, especially with the "old" mechatronics and computer science!


- Ah! The two of you are wrong! It has mechatronics, electronics and more! I’ll explain: the idea is not simply a fountain of lemonade, but a "micro-controlled fountain of lemonade"!


- Microcontrolled? - the two boys asked at once, quite surprised.


Professor Ventura went to the blackboard and prepared for a better explanation than he intended:


- The idea is simple! I already have it in my head: let's put a 1,000 liter tank in the square and fill it with lemonade. At the exit a small faucet will be activated by a solenoid automatically when the plastic cup is placed in position to fill the cup with the liquid. My additional idea, with which the preboste, I say the mayor, doesn’t know, is something really impressive using automation and more...


- Whoa! - exclaimed the cautious Bart, who knew that from time to time the professor's enthusiasm should be restrained!


- Do not worry! - The professor calmed him down - What I want to do is to put a sound circuit coupled to the system. So every time the tap is turned on and fills in a glass of lemonade, an "advertising message" of the product is emitted through a loudspeaker.


Bert was surprised:


- Advertising message?


- Yes, something like "Drink lemonade with lemon from Lemon city, the sweetest sour in the world!”.


For those who improvised, the message was very good! Bert wrote it down to suggest it to the mayor, but there was still the technical problem of the recording. How could they solve it?


The professor had the solutions. The next day he bought two basic elements for his project at Mouser Electronics. His order was an electronic device which would be ideal for their advertising message project: a digital sound recorder and an Arduino board!


- It's settled! I got a digital recorder and an Arduino microcontroller board!


- Digital recorder? - Bart and Bert had no idea what that was, and the teacher had to explain:


- Calm! I'll explain when it arrives.


In fact, two days later, when the professor should go to the City Hall to present his project to the mayor, to get the funds cleared, a small package arrived in the mail.


Professor Ventura, along with Bart and Bert, opened the package and there it was: a small printed circuit board containing a chip. It was the digital recorder! The other was the well-known Mega Arduino.


- Very well! - said the professor, carrying the devices to his benchwork where he put the 4 batteries in the holder of one of them - This is a digital recorder!


- Digital recorder! - Bart and Bert were greatly surprised.


- You are used to old tape recorders where sound is recorded on the elemental magnets of a magnetic tape, and then has to be moved to be playback. Not this one! No need for mechanical movements!


- Yes, this "thing" has no engine, no apparent mechanism! - Bert had noticed that.


- In the digital recorder, the sound captured by this small microphone is converted into digital information, that is, "numbers" that are recorded in a RAM memory, similar to those used in computers! This way, to reproduce the sound, the circuit "reads" the memory and converts the numbers back into sound!


- Interesting! Is the sound on cellphones also recorded this way?


- Yes, and other digital media. But there is one problem to be considered: Because sounds are complex waveforms, converting a few seconds to recording takes up too much memory space. See, with a memory of 1 megabytes (one million stored numbers), we can "record" just over 1 minute of sound!


Professor Ventura gave a small demonstration: he spoke in front of the microphone and then pressed the play button: the device reproduced his phrase with good fidelity! He went on:


- Too bad it's not for long-lasting recordings! - commented Bart.


- True, but similar media is being created which can record music for a long time. This is the case of MP3. Thus, these smaller memories are more often used in recording small messages, for example, in answering machines or even in advertising messages and talking toys. I saw articles showing that it was used in an interesting device, installed in a supermarket, to attract the attention of customers: when someone walked by the product on the shelf, a photocell detected it, and a message calling attention to the product was issued!


- Ingenious! - commented Bart - I also begin to understand how this device could be used in our "lemonade fountain"!


- That's right! In our case, simply timing the trigger, couple it to the solenoid which opens the tap and we're done! We just need to boost the sound with an amplifier to get the message out! After all, advertising is the lifeblood of business!


The overall idea of ??the project was already established. Right after it was taken to the mayor who, marveling at the demonstration of the "gadget", approved it immediately!


- Just one thing! - said the mayor - Your message is good, but your voice sound like "a re teen shrimp if it could talk", so let's use our announcer. Eddie Mupy, a powerful voice from our FM station, Lemon city's "golden throat" is ideal! I'll call you when the set is ready for the record! Right?


- Right!


Everyone agreed and the assembly work of the "lemonade fountain" began.


The movement in the square was great! In addition to the rounded container, which was shaped to look like a large lemon, ornaments were placed everywhere. The professor worked on the tests of the conjugated solenoid recorder. A photo-resistor received light from a small light bulb. When the glass interrupted the light beam, the Arduino programmed as a timer triggered a relay. The dual-contact relay triggered the solenoid and a second timer, which was connected to the digital recorder.


The professor, very methodical, did some calculations aloud:


- Every glass of lemonade is about 100 milliliters, which means we have 10 glasses per liter! With a thousand liters in the container we'll have ten thousand glasses of lemonade available! If 5 thousand people come on the big opening day, each can take up to 2 glasses without problems! Of course we'll have more lemonade to refill, if necessary.


The news of the event was the main subject of the city and again the Musical Corporation of Lemon city had an important role.


Maestro Ronald, however, had a serious problem! He was not able to convince Tubald Weathercock to attend the event with his tuba:


- I don’t play anymore, and that's it!


- But, Tubald! Without you the "band" does not exist. And besides, we don’t have a substitute in the city!


Ronald knew that Tubald's "moral" was badly shaken by what happened in the case of swallows and the light fountain, but he needed the full band! Trying to "soften" the musician, Ronald told what was to be done, and that this time, the fountain of lemonade could not cause any harm, because all precautions had been taken, and that he could play without problems! He made sure himself it would be safe!


- Even with crazy Professor Ventura in business?


- Yes, I assure you!


At that moment, the maestro did not notice a strange glow in the eyes of Tubald, who surprisingly changed his mind and agreed to play:


- Okay, I'll play!


The conductor left Tubald’s barber shop without understanding why the tuba player’s behavior had changed so fast! The musician had realized that the time had come for his revenge, and not only that: he already knew how it would be done!


The installation work continued for several days, in the hustle of the come and go from the bricklayers, carpenters and electricians, as well as Professor Ventura, Bart and Bert. There was even a crew from an American TV program, from a Florida orange-producing city, who considered itself the "citrus sister" of Lemon city. However, with the intense movement, no one noticed that a certain small person approached the place several times and, with great interest, observed everything, especially the huge water container in the shape of a lemon, where the lemonade would be stored!


The mayor, worried about what might go wrong, took precautions with safety: even at night, a guard was on duty in the square, which was not a concern to Tubald, on the contrary!


Another fact, which was not very noticeable, was Tubald’s eight trips to the neighboring cities. Mysteriously he visited the pharmacies of these cities and in each one always bought the same medicine!


- Give me two glasses, so I do not need to come back here!" I live far, you know? - was what he told pharmacists, as he said the name of the medication.


He had already stored 16 glasses of the mysterious “drug” in his house and, as incredible as it may seem, was not for the prevention of any problem that any madness of Professor Ventura could cause!


Tubald took part in all the rehearsals of the band, playing his tuba with potency, but as his companions noticed, he was quieter than the normal: the former talkative Tubald Weathercock no longer said his jokes and, as soon as the rehearsals were finished, he went in a hurry to his house!


The day before the big party, the lemonade was prepared and placed in the main reservoir. In a second container, were stored another thousand liters, in case it was needed.


- We don’t want anything to go wrong, so let's do things in advance and test everything!


The mayor was right this time, with what the professor agreed. After testing the automatic system the two were satisfied with the results!


- It's great! - said the mayor, with the glass in his hand, while a powerful loudspeaker in the lemon box said his advertising message in the loud voice of Eddie Mupy:


“Drink lemonade with lemons from Lemon city and lots of sugar, the sweetest sour in the world! ... Drink it as you please and be happy!"


The message had been slightly modified, but it was great in the musical voice of the famous local FM announcer! Happy, the teacher and the "preboste" of Lemon city went to their homes...


That night, however, after the band's final rehearsal, Tubald didn’t immediately return home, and no one noticed that he, in addition to his tuba, was carrying a sport bag which seemed quite heavy.


Stopping in the square he pulled off a conversation with the guard who were on duty! His "old friend" Christopher Openedeye!


Unlike what the old man's name indicates, he was already sleepy, and Tubald would make him sleep soon.


- Good evening, Christopher! It’s a "Boring" job to be a guard, right?


- Truth! No one comes to talk and if I’m not careful I end up sleeping!


The guard said this sitting onn the chair he had placed right on the side of the lemonade tank!


Talk comes and goes, Tubald ended up offering some coffee to the guard from a thermos bottle he took out of the bag!


- Good thing! Nothing better than some coffee keep me awake!


Good thing? What the poor watchman did not know is that Tubald had put a strong sedative in the drink! Pretending to accompany the guard, he simply threw back the contents of his plastic cup!


In the third little cup, after much chatting, the guard gave away and leaned back on his chair, sleeping soundly!


Tubald then took the moment to climb the ladder behind the container and from his bag he took 16 large bottles of ... "Unblock", a potent laxative, which he emptied completely in the lemonade!


And that's how the Lemon city's 200-year-old "anniversary" lemonade turned into a "potent" purgative lemonade!


Tubald put the empty bottles in his bag, closed the container, feeling happy and satisfied with the tuba under his arm and whistling Sousa's "Stars and Stripes", he returned to his house!


The great day had come! Early in the morning, the City Hall sweepers were careful not to leave any dust in sight! Everything was spotless! They were only a little surprised to find old Openedeye still sleeping on his chair beside the container. He got frightened when he was awakened, and as soon as he recovered he went home still feeling a little dizzy.


In the afternoon, the American TV crew set their recording equipment on a small stage. The imposing presenter made the first tests with his microphone.


Satur, the busy "prebooste", was still giving orders at the City Hall, while in his house, Tubald prepared his special equipment to take to the square!


- Is that even necessary? - asked Mrs Ginevra Wathercock.


- Yes, from what can (and will) happen, it is good to be prepared! - and continued to shove some strange objects into his sports bag ...


An hour before the festivities began, the square was already full and the Glorious Musical Corporation of Lemon city already cheered the atmosphere with its marches. Tubald played concentrated, but with a devilish look, which none of his companions noticed.


The opening speech of the festivities made by the mayor, and of course, was inflamed. No words were spared to praise Lemonion Pluckwood, the founder of the city, and his statue in the square which pointed to the west, where he actually wished to conquer, if he had not tripped on a "damn lemon"! He was retained some time on that spot because of his injuries and founded Lemon city! Finally, the mayor, showing the people the "fountain of lemonade" ... "From where would flow all time ... the precious liquid to quench the thirst of the people from Lemon city and its visitors! ..." he invited the crowd to line up and help themselves.


The plastic cups of lemonade rolled on and on, the band played and the powerful voice of Eddie Mupy kept repeating the advertising message!

Time passed and the tank emptied. Tubald played, but in the background he laughed, much more attentive to what happened in the square than in the music itself, but nobody noticed it. They also were not surprised when they offered him a glass of lemonade and he did not accept.


By then the lemonade began to make effect.


The first faces of the crowd began to change color and some people were already feeling quite "weird". The mayor, who, in his enthusiasm for advertising the "product of the city," had drunk more cups of lemonade than he must have, begun showing the first symptoms that Unblock was working very well!


But the first to "preshit" himself was not the mayor. Frank Beans, a rather "bulky" individual, whose nickname was a consequence of the exaggerations from eating and drinking, and who had drunk at least 15 glasses of "potent" lemonade, stopped at a certain point in the middle of the square in a very strange way... Everyone saw him, staring at a point in the infinite, gathered his eyes, made a "suffering" face and then, arching his legs, bowed strangely and with an unpleasant noise… he shitted himself!


It was enough to start a new "chain reaction" which exploded too quickly for anyone to escape.


In a few seconds, once again, the mayor was "struck" under his feet and the same voice, known to all, spoke to the crowd:


- Hey! This is getting too usual! The preboste "preshitted" once more!


The desperate mayor realized then, but too late, that he had made a tremendous mistake a few days earlier: when Mrs Linda, his secretary came to him to sign an important document, worried about the festivities he simply dismissed her:


"Not now, Mrs. Linda!" After! - and there was not an after!


He remembered now that the document determined the renovation and extension of the toilets of the square! It was completely without toilets!


Again the confusion took over the crowd, aggravated by the absence of toilets. This time, we cannot say that there was panic, because it seemed that the inhabitants of Lemon city were getting used to it!


But the most interesting thing was happening at the container, where Bart and Bert, also affected by the lemonade, tried to turn off the tap, solenoid and recorder.


Frank Beans was close by, and hadn’t "unloaded" everything! Still dizzy and unbalanced by the effect of the Unblock, he felt a new "squeeze" and half bewildered, leaning on the small control box where the digital recorder was, inadvertently triggering the controls. What happened then was very interesting... Professor Ventura had not removed the microphone from the device after the recording, and when the heavy individual leaned on the device the internal switch moved from the "play" to "record" position for a few seconds...


That was enough for the program sequence to change and in the middle of the message there was a strange noise picked up by the microphone... A "beautiful" "pffrrrrrrrrrrrrr ... rrrrrpttt! ... splash!" from the new and great Mr Beans "preshit"!


Everything would be fine if the unit was turned off, but the impact with the box "locked" and in the middle of the confusion the speaker started repeating without interruption the altered advertising message, in the powerful voice of Eddie Mupy:


"- Drink lemonade with lemons from Lemon city and ... pffrrrrrrrr .... rrrrpt ... splash! .... be happy!" - except that under the circumstances, no one was happy.


The American TV crew, who recorded everything, was not quite understanding what was happening until the handsome presenter, with the microphone in hand, felt the effects of the many lemonades he had drunk and making a very worried and sad expression when he felt the " strange slimy liquid" flowing down his legs, he exclaimed in a choked voice:


- Oh! My God!


I don’t even have to say that the recording ended there, with the team hastily leaving the place.


In this confusion, the calmest personl was Tubald Weathercock! At the beginning of the mess, opening his sports bag he took out the strange "protective" objects he carried: a pair of "rubber boots", a waterproof cape and an umbrella! Wearing the cape, putting on his boots and protecting his precious tuba with the umbrella he hurriedly left the place impeccably, without a splash even to moan! He was avenged!


Professor Ventura was desperate:


- I’ll be blamed again!


But, he had an alibi: he had also "preshitted" himself right beside the mayor!


The confusion continued for a long time with dirt and people slipping on it everywhere and the speaker repeating the message.


"Drink lemonade from Lemon city and ... pffrrrrrrrr ...."


The square was once again emptied, dirty and smelly, and only became silent when Professor Ventura, Bart and Bert, with great effort succeeded in deactivating the speaker system of the container.


- And now? - It was the first thing that Bart said looking at the professor.


- Well, for the best we should disappear again for a while!


That's what they did!


While in all the houses the scenes were of disgust, desperation with everyone looking to clean themselves or even going quickly to the bathroom, there was a place where everyone was happy: at Tubald Weathercock’s home, he and his wife would laugh at what happened for quite some time.


But the mayor's problems were not over: the next morning, the group of officials who were to clear the square was on strike in front of the City Hall, with banners demanding "insalubrity extra" pay and "gas masks" to do their job.