Margaret doesn't usually have magic accidents. But this time she was holding her whole rune dictionary and also an unlabeled thing she found in the magic shop, and she really wanted to see what the thing did as long as it wasn't fatal, and now she is somewhere unexpected. If it turns out that the thrift shop thing was a teleporter that'll be kind of disappointingly redundant but not actually a problem.
"The wings are shaped like..." Urtho frowns intently, hands darting in the air. "You will have to draw it for me, I think! And what drives them to go so fast in the first place?"
"I don't know if I could draw one well enough to show something that would actually work; the exact shape matters a lot. But they get their propulsion by burning a kind of fuel that burns very hot and makes the air expand and then forcing that air out the back of the engine, which pushes the engine forward."
"- Huh." Urtho leans forward, eyes sparkling and intent. "Fascinating! Can you draw me a diagram of that?"
"I think so. A simple one, at least; modern ones have all sorts of tricks to make them go farther on less fuel."
"Oh, how clever! Here you go." He takes a notebook from his pocket and opens it on the table for her, then glances around helplessly.
One of the little hertasi is waiting nearby and, without even asking for clarification, produces an inkwell and quill pen for him.
"There you go!"
She sketches a simplified cutaway view of a jet engine, and a wing, and also a propeller. "Older planes used their fuel to spin one of these; the blades are angled so they pull air from front to back."
"Wow! Do the blades need to be an exact shape too, or are they just flat pieces at an angle? If it's only the angle, I think we could arrange to test that and figure out the right angle even if you're not sure of it."
"No, those need to be the right shape, too, they're kind of like tiny wings." She wonders if she could make a magic wind tunnel and try to figure it all out.
"Goodness! That sounds so complicated on so many axes - how did your civilization on Earth ever manage to figure it out?"
"Experimentation! And there are lots of us, and at least in some countries the economy is good enough that some of them can spend their time on stuff that might take a long time to pay off."
"How wonderful!" Urtho spends a few moments staring at her engine diagram in awe. "- What else? There must be so many other things that were revolutionized, I cannot even think where to begin... Can your world build very tall towers? Here we can really only do it only with magic."
"We can!" She talks about concrete and rebar and steel, hundred-story skyscrapers with more window than wall because all their strength is in their core.