To be precise, it's not a proper "Finnish wood stove" because the wood is too fresh.
Fresh wood contains a lot of moisture, making it difficult to ignite and generating unnecessary smoke. However, the difficulty is relative because the wood doesn't need to be completely dry to catch fire. After all, how would forest fires spread? Trees that burn in wildfires are also fresh.
Tom's match instantly lit the twigs and dry leaves placed in the center of the assembled log, and a little smoke began to emerge from the log.
"It's burning, it's burning!" Mr. Weasley exclaimed like a child, waving his hands and feet. For him, lighting a fire in a Muggle way was a completely new experience.
He took Tom's matchbox in his hands. "I'll give it a try too!"
However, like many children using matches for the first time, Mr. Weasley couldn't get them to light. He was puzzled, as Tom had succeeded with just one attempt, but he couldn't manage it no matter how hard he tried.
The matches broke or wore out in his hands, losing the igniting part. The sandpaper on the matchbox was completely worn down.
Mr. Weasley sighed deeply.
Tom stepped closer and tossed the scattered matches on the ground into the wooden log, reviving the fire.
Finally, Mr. Weasley managed to light a match, but the sudden burst of flames startled him, and he dropped the match on the ground.
Onlookers: ...
Fred couldn't help but cover his face with his hands.
"The sandpaper on this matchbox is no good anymore," Hermione said gently, taking the matchbox from Mr. Weasley's hands and showing him how to do it.
"She'll make an excellent mother someday," George remarked as he listened to Hermione's patient explanation, making his own judgment.
Under Hermione's guidance, Mr. Weasley finally learned how to light the matches. He continuously lit them and threw them into Tom's wooden log.
By this point, the inside of the log was already ignited, and the smoke coming out made it difficult to keep their eyes open.
The principle of this stove was to allow the flammable material to ignite the core of the log, then gradually carbonize and form a coal fire that would continue to burn, effectively extending the burning time of the wood. In the end, the inside of the log would burn away, leaving a large triangle-shaped hole.
"Cough, cough... the fire is already burning," Tom said as he stepped back from the burning wood.
"The Finns insert a Z-shaped pipe into this hole," Tom explained, pointing to the log, "one end is outside the wood stove, and the other connects to the tent. This way, when the cold air from outside passes through the wood stove, it heats up and becomes hot air, which is the heating principle of the Finnish stove."
Mr. Weasley nodded repeatedly as he listened, now understanding how Muggles without magic survived in cold, snowy climates.
"It's important to note that the air intake of the pipe should be outside the wood stove," Tom began to provide some safety explanations, as he wasn't sure if wizards had the concept of carbon monoxide poisoning; he felt they did, as all the chimneys at Hogwarts had ventilation to prevent tragedies where students would be trapped on winter nights.
"Ah, now I understand! Tom, you're quite well-informed," exclaimed Mr. Weasley excitedly, feeling like he had learned a lot of knowledge that he didn't know when he could apply. He patted Tom on the shoulder and said, "By Merlin! Where did you learn all these things?"
"Uh, all of that is common knowledge among Muggles," Tom replied in that manner while observing the strange looks from the Grangers. "After familiarizing yourself with Muggle science, you realize many things that aren't common sense, like the fact that houses made of ice and snow aren't really that cold inside, or that the 'gas' you see when a kettle boils isn't actually gas."
Seeing the Weasleys' looks around him as if they were attending an advanced mathematics class, Tom knew they hadn't paid much attention. And he couldn't blame them. After all, why had wizards only attended magic classes from a young age? In most of the magical world, there are no natural sciences, and they simply can't grasp the physical principles and have poor logical reasoning when it comes to understanding the nature of the world.
The solution might be to offer a mandatory course at Hogwarts where students learn some basic physics and chemistry. As for mathematical calculations, that skill could be complemented through Arithmancy divination, where numerous operations are performed. Inadvertently, wizards would end up reviewing mathematics.
At that moment, the smoke coming from the wood stove had stopped, and a flame was rising from within it, indicating that the wood stove had been successfully lit.
After a while, Harry and the others returned with a kettle. Tom placed the kettle directly on the wood stove to heat water and prepare tea.
The waiting process for the water to boil wasn't boring. Their tent was located next to the road leading to the Quidditch field, where many Ministry of Magic officials were busy. Mr. Weasley was quite popular at the Ministry of Magic, and many officials would stop to greet him as they passed by. Mr. Weasley made an effort to introduce all the officials to Tom, Harry, Hermione, and the others.
That was the invisible advantage of coming from a pure-blood family. Although the Weasleys were poor and couldn't afford to buy textbooks, they were still an ancient pure-blood family and had a presence in the lower levels of the Ministry of Magic.
Director of the Goblin Liaison Office, members of the Experimental Spell Sub-Committee, Memory Modification overseers, Unspeakables... Tom was getting to know one Ministry of Magic official after another.
When the water boiled, Mr. Weasley prepared a teapot of tea, a pot of porridge, made several fried eggs, and hung sausages on the wood stove to roast. The way they roasted the sausages was wonderful, as the sausage fat slid over the top as they cooked, thoroughly infusing them. In the end, the sausages looked roasted but tasted fried. In addition to the sausages, they also roasted potatoes, making the most of the heat and fat.
The fatigue from the early morning walk had completely disappeared.
Tom held a skewer of sausages in one hand and a bowl of porridge in the other, sitting on the ground next to Fred and George.
"Everyone here is a wizard."
"Yes," replied Fred as he cut the roasted sausages and placed them between two slices of egg.
"They're all potential customers," Tom said, taking a big bite of sausage.
"We know, but they confiscated all our Skiving Snackboxes," George frowned and drank the porridge in one gulp, as if the vegetable rice had tasted like bitter wine.
"I wouldn't have suggested selling Skiving Snackboxes here; think about all the kids here, their parents would kill you if they ate them by mistake." Tom shook his head and seemed to have a good idea.