Xenia led Eisen down one floor of her tower into a mostly empty room. There were some objects stacked up on a pile on one side. They were artifacts that Xenia had worked on to practice her enchanting and to test out some of the ideas she had.
In the center of the room, drawn out onto the floor, was a permanently installed magic circle that created a circular barrier within the space. And inside of that barrier, it was possible for Xenia to plan out enchantments in high detail to try and figure out how to best construct her more complex patterns. Using her methods, she had created some techniques that were very different from Eisen's own.
All of his techniques were, at the end of the day, still 'physical' in nature. It was all about carving everything into the base material. For someone like Eisen, a craftsman through and through, that was the best method to get everything working properly. Since enchantments were a sort of magic, the mental image and confidence were two major aspects in their creation.
However, a person like Xenia, someone who was an expert in working with the mystical and magical, wasn't quite restricted in the same ways. Of course, her enchantments still required a base material for it to be attached to, but her method of enchanting as well as the way she created her own patterns wasn't necessarily as direct as others' methods.
Though, that also made her enchantments much harder to reproduce, which was both good and bad, depending on the goal. But for now, in the conceptualization stage, it was fine for her techniques to blossom as much as she wanted.
"Alright, where are we starting?" Xenia asked, looking at the old man to her side, who was already thinking about exactly that.
"I guess it's probably not a bad idea to start with the engine. There's two main directions to consider; a physical or magical approach."
"Going with a fully magical approach would be much too expensive at the scale we're talking about. Since others can't create mana-generators in the same way you can, it needs to run on other sources, like mana crystals."
"In that case... let's take a combustion engine as an example. Fire magic is readily accessible, and fairly cheap from a mana perspective to boot," Eisen suggested. Xenia stepped into the barrer in front of the two, moving her arms around. A complex pattern started appearing in front of her, as a model of a simple piston appeared.
Neither Eisen nor Xenia really knew the ins-and-outs of engines, but they at least knew the most basic mechanics.
A combustion motor held a chamber confined mostly by an air-tight piston. In that chamber, a controlled combustion of fuel would then happen, which would force the piston down along a cylinder.
Xenia quickly did as suggested, but slowly looked at Eisen, "But that's already bringing up the complexity of the enchantment a lot, not to mention the mana cost. It would be pretty efficient though, I'll give you that."
"When using multiple elements, it's always easy enough to improve the mana efficiency by regulating the exact ratios, right?" Eisen pointed out, "We just need to figure out a point where it's efficient enough to make up for higher mana cost. And I know I brought it up first, but the complexity of the enchantment should be secondary, since we can build some tools to make up for that."
"In that case..." Xenia altered the enchantment in a few minor ways, until the model was ready to show off exactly how powerful it was. For the regular amount of output that was given, the amount of mana that was used was actually a lot less than any of the other examples so far, now that the enchantment was a bit more fine-tuned.
Of course, with the complexity of the enchantment, the production cost itself would go up a lot, requiring four different elements to be used instead of just one. It was easy enough to find people with these elements, but it was of course always cheaper to buy access to just a single element than four.
"...For now, let's put the production cost aside. That's an issue that we can potentially solve through Komer somehow," Eisen suggested, running his fingers through his beard in thought, "What about the rest of the process? Should we enchant the sides of the cylinder, or should we use some sort of grease?"
"Well, enchantments require more mana, obviously, but if we use grease they would need to replace it all regularly, right?"
"Right, but that's also not really an issue... the trains will need to be serviced regularly anyway to make sure everything's in working order, so replacing the oil or grease wouldn't be a massive issue."
Xenia thought, moving her fingers to try and create a test-enchantment on the model's cylinder, "If we want to increase the efficiency and longevity, we can still use some enchantments. If we're ignoring the complexity and production cost for the time being, then the enchantments would be a great way to improve the efficiency of the overall piston.
We could reduce friction to basically completely zero."
"...That would also improve the longevity of the the materials," Eisen thought, "Alright, let's go with something like that, then. With the type of grease I have in mind, we should be able to make a tool that produces it as well, given the materials. So we could make that part of it a lot cheaper on the production side of things too."
The two stood in the tower attached to the side of the castle, continuing to discuss different methods, techniques and ideas for the trains, almost all the way through the night.