The Magical Principles of Natural Philosophy at Hogwarts

When Erwin entered Gringotts again, he was pulling a compact black suitcase.

This small box, which has been cast a traceless expansion spell, can pull out two storage cabinets with a height of two meters after opening, providing sixteen storage compartments, each compartment can store three times the actual capacity of items - no

Wrong, the space that has been stretched without a trace is stretched again without a trace. Erwin likes this matryoshka concept.

However, the price of the matryoshka doll was several times the price. The suitcase cost him two hundred and forty-six galleons, which was almost twice what McGonagall said a normal student would spend in a year. Erwin's overall assets dropped by a hundred.

Ten out of ten.

But this is a necessary investment. After all, how much he can bring to Hogwarts depends on the capacity of the suitcase.

Two thousand seven hundred and fifty-four Galleons only occupied half of a storage compartment, and Erwin could not feel the weight of these gold coins at all when pulling the suitcase.

"Of course a suitcase with such a large capacity will be subject to a weight-reducing spell at the same time," Professor McGonagall told him, "No matter how many things you put in it, the weight of the suitcase will not change."

Professor Stewart on the side wanted to pluck out his beard. Such a box was enough to cause an earthquake in the entire physics community, but it was just a daily necessity for these wizards.

"Then how long can the traceless stretching spell and weight-reducing spell of this box last? I think if these two spells fail, it will definitely lead to very serious consequences." Erwin asked.

"It depends on the materials. They will prepare a special potion and apply it on the interlayer to maintain the effect of the spell. Since your suitcase is worth more than two hundred galleons, it should be able to be used for at least fifty years."

"Professor McGonagall," Hermione raised her hand in an effort to show her presence, "why not cast the Seamless Stretch Charm on a smaller container? For example, a storage bag would definitely be more convenient than a suitcase, right?"

"Only containers with a stable structure can be cast with the Seamless Stretch Charm, so bags are not suitable. In addition, the smaller the container, the more difficult it is to cast the spell."

"If I remove all these storage compartments, does that mean I can put Hermione in them?" Erwin fiddled with his suitcase while ignoring Miss Nutria's glare.

"No, the Ministry of Magic prohibits packing living creatures into small and medium-sized traceless expansion containers. This is a lesson learned from the lives of nearly fifty wizards in history."

"Does this mean that large containers, such as buildings, will be relatively safer? The store I just sold has tents for sale."

"You can understand that, but the size of the container is not the only factor that affects security."

"What happens if the stable structure of the seamless expansion container is destroyed? For example, an ogre or a troll or something crushes my suitcase?"

"That will produce a small explosion, and all the contents of your box will be ejected. Well, Mr. Erwin Frost, if you are very interested in the Traceless Stretching Spell, you can do it in your senior year.

Make this your research direction. Now it's time to buy your wands."

Professor McGonagall ended the endless questions forcefully. It was obvious that no matter how good her temper was, she could not withstand Erwin's strong thirst for knowledge. She walked forward, completely unaware that the boy behind her was already thinking about putting him in his mind.

The feasibility of filling a suitcase with TNT and then throwing it out.

The place where wands are sold is a small and shabby shop, and the gold-lettered sign on the door has peeled off, "Ollivanders: Making fine wands since 382 BC." Hermione read it word for word.

The shop owner was an old man with light gray eyes. "These must be the last two Muggle students, Minerva?" he greeted Professor McGonagall.

Professor McGonagall nodded, "Excuse me." She said politely.

The old man looked at Erwin and Hermione, "Which one of you comes first, kids?"

Erwin silently took half a step back.

Ollivander began to measure the bewildered Hermione. The measurement items were many, complicated and strange. At the same time, the old man was still chatting with Professor McGonagall.

"That kid came to buy a wand a few days ago."

"Potter?"

Erwin's expression moved slightly. This was the second person he heard the boy's name from.

"Yes, holly wood, eleven inches long. What's interesting is that the phoenix tail feathers at the core of the wand come from the same phoenix as the Dark Lord's."

Professor McGonagall was silent for a while, "Maybe this is fate." She sighed.

Ollivander began to let Hermione try using various wands. She only needed to wave them briefly to judge whether they were suitable, and soon had a satisfactory answer. A wand appeared when Hermione held it.

Violet brilliance.

"It's wonderful." Ollivander was very happy. "It seems that we are choosing the wand, but in fact it is the wand that chooses the wizard. This is a good wand, grapevine wood, dragon's nerve, ten and four quarters."

Three inches long, very strong, suitable for a skilled and brave wizard, very good."

Miss Nutria was obviously very satisfied with such praise, and she smiled at the corner of her mouth, while Erwin suspected that this might be the same as horoscope divination, and he would not say anything unpleasant at all.

It was Erwin's turn, and he had reservations about choosing a wizard for the so-called wand. After all, he had used the ebony wand left by Marduk many times and didn't feel anything uncomfortable at all.

After all, the wand is just a tool. Erwin subjectively feels like a long bow, and magic power is like arrows. It is of course easier, more accurate, and more powerful to shoot arrows with a bow, but if you have strong enough arms, you can shoot arrows with your bare hands.

It's not impossible to throw the arrow out.

One wand after another was delivered to Erwin's hand, and then quickly taken away. Ollivander looked solemn at first, and then began to sweat on the tip of his nose.

"That's impossible," he said suddenly. "Every wizard should have a wand that suits him."

"Are you saying that you can't find a wand that suits me?" Erwin shrugged, "Isn't this a normal phenomenon? You only have more than a thousand wands in stock here, the number of samples is too small, and you seem to only start from

Materials are taken from three animals: dragon, phoenix and unicorn. I think things from these three creatures are not the only ones suitable for making wands."

"I can confirm that you are suitable for dragon materials." Ollivander was a little angry. This was the well-founded anger that arose after being questioned in the professional field.

Trying a wand every half minute, this process was repeated for more than an hour, and everyone except Ollivander's expressions gradually became dull.

"Otherwise, just choose a reasonably suitable wand for him." Professor McGonagall said cautiously.

Erwin fully agreed with this. If he stayed any longer, he would just continue to suffer. "In fact, you are not choosing the most suitable wand for the wizard, but choosing the one in your wand inventory that is most suitable for your customer."

He tried to persuade Ollivander, "In this case, there is no need to strictly require that the wand must glow when it is in the wizard's hand..."

Even eleven-year-old Hermione could see that this kind of persuasion was really ineffective.

Ollivander finally gave up, and the old man's face turned a little gray. "It seems that I really don't have a wand suitable for you, child." He announced, while handing over a long box, "Take this, Yue.

Osmanthus wood, dragon heart string, twelve inches, this is the best performance in your hands before."

"It's very good. It has the same wand core as Professor Dumbledore." Professor McGonagall said,

Erwin took the box and said, "Then, can you sell me other wands that work well in my hand?"

Ollivander and Professor McGonagall both looked at him with strange eyes.

"What's the problem?" Erwin was a little confused, "Don't businessmen want customers to buy more?"

"You can't recite a spell with two wands," Professor McGonagall reminded: "That won't double the power of your spell or cast two spells."

"But there should be a special spell for wands, right?"

"Indeed," Professor McGonagall pondered for a moment, "Expelliarmus can directly disarm the wizard who was hit."

"Obviously, then, the best way to deal with the Disarming Curse is to immediately pull out another wand."

Professor McGonagall was silent for a while, "Are you worried about having to fight other wizards when you go to Hogwarts?"

"A little bit." Erwin shrugged, "In addition, the wooden wand is not strong and the possibility of damage is not small, so I think a spare wand is necessary."

"My wand has been used for almost sixty years." Professor McGonagall said expressionlessly.

"This is obviously an isolated case." Erwin said plausibly. Hermione looked at him with surprised eyes. In the past two days, she found that there were so many things about this boy that were different from ordinary people.

Ollivander stared at Erwin for a while, "Generally speaking, excellent wands are exclusive and will not allow their owners to hold other wands. But since you don't have the most suitable wand, you can indeed ignore this restriction, then I

There is no reason to reject you."

He gave Erwin three more boxes, "Oak, dragon's nerve; walnut, also dragon's nerve; holly, dragon's heartstring. I don't charge you for these three wands, I just ask you to come to me every holiday."

, I will find a wand that suits you, and you must return these wands to me when the time comes."

Apparently he saw Erwin as his professional challenge.

"Is that so?" Erwin scratched his head, "Then I'd better pay."

Walking out of Ollivander's shop, Professor McGonagall looked at Erwin thoughtfully and said, "I have a feeling that you will be one of the most troublesome students in the history of Hogwarts."

"Thanks for the compliment."

The next step was to buy school uniforms. The clothes provided by Madam Malkin's Robe Shop had no magical effect, and Erwin was a little disappointed. Then there was the cauldron, which was nothing special. Erwin felt that it would be better to go to an ordinary workshop to customize it, at least.

No need to spend precious Galleons. As soon as you enter Flourish and Blotts Bookstore, you can see a row of men with bright smiles on the bookshelf. Erwin doesn't understand how narcissistic someone is to have his photo printed on the cover.

At the same time, this also made him realize that there should not be many professional books in this store.

"The library collection at Hogwarts can be said to be the richest in Europe, so you only need to buy textbooks."

For the first time, Erwin felt that Professor McGonagall's voice was so pleasant.

There is only one last store left that I haven’t been to, the Eela Owl Store.

"I suggest you buy an owl to send letters. Of course, the school will provide owls, but it's not as convenient as having one yourself."

Hermione discussed it with her parents and said, "I still won't buy it." She finally made her decision.

Hermione's family was in the city, and to their neighbors, it was really strange for a girl to keep an owl as a pet.

Erwin had no worries about this at all, "The most important means of communication between wizards is through owls?"

"Yes, a well-trained owl can help you deliver a letter to anyone, as long as the other party does not take the initiative to hide itself."

"Then I must get one."

He could use the public owl at school, but what about during the holidays? The owl was probably his only means of contact with the magical world.

Facing a room full of owl-shaped animals, Erwin chose the strongest eagle owl without hesitation. The reason was very simple. This guy was the biggest and should at least have the strongest load-bearing capacity. He didn't notice the other side.

The clerk's expression was hesitant to speak.

At this point, everything on the list has been purchased.

Before leaving the Leaky Cauldron, Professor McGonagall gave them two tickets, "On September 1st, the entrance to King's Cross Station is between Platform 9 and Platform 10. There is a hidden barrier. You can go directly through it when the time comes."

Just go over there."

She explained everything that needed attention.