Nod nod.

Even more whisper-like this time: "Have you ever heard before, of an 'engine'?"

Headshake.

"Ways of converting energy into force. There's... I could pump water anywhere, as much as you wanted, if nobody would mess with the machinery. Would just need some jolting once it's built. Or coal. My other idea might not need the jolts, either- I could do it with coal instead, I was assuming it wasn't available, earlier."

Shrug at "pump water anywhere". Nod at coal. They sure have that.

"That's all for later though, I guess."

Nod nod.

When they've emptied their stew bowls very thoroughly - it's apparently customary to swipe out the dregs with your finger - Belmarniss takes them and brings them back.

She's already having vaguely Sparky thoughts about chemical synthesis of sugar.

And then Belmarniss can bring her home - it's a long walk, she has to refresh the light a couple times - and explain her houseguest situation to her mother.

(She is honestly too tired to be putting much effort into learning the language. She tries to be polite-if-distant. The darkness is terrifying each time it comes. She's definitely going to work out a torch early on.)

And then in her own room Belmarniss can wad up a cloak and offer it to Waltana as a pillow. She herself sleeps in a silk hammock.

Just relax. Don't keep shifting around. Loosen your grip on the wound-up saw. It's already dark, so may as well close your eyes. Stop clenching your jaw.

Her head still hurts a whole lot. Little stings from the head-gulfer's skin, a dull roar of a headache, lingering soreness from the ice spell...

She falls asleep eventually, though.

She will have the opportunity to wake up to Belmarniss receiving breakfast from a tiny light-bearing person. There is some for Waltana too.

Five more minutes.

Ugh. No. Fine. She's awake.

"You probably don't have Comprehend Languages up right now."

...Point at ear, headshake, inquiring sound.

Cast! Attentive look! - Light cast on that pebble over there!

"Oh, sorry, I was confirming that you weren't using it right then. Now I have to say things."

Snort. Shrug. Breakfast breakfast.

"Could try to start explaining engineering- The slate and chalk over there will help."

-But first, breakfast, yeah.

When they've eaten Belmarniss passes her the chalk and slate.

She spends a little while on it.

Kinematics
--Acceleration, velocity
--Friction & Pressure
--Momentum, force balance
--Torque & rotation
--Static Analysis

Conservation
--Energy
--Momentum
--Mass
--Concept of "force-work"

Materials
--Chemistry Fundament
--Stress & Strain
--Tensile vs Compressive

Lightning & Magnetism
--Where do I even start?

Actually using it
--Tolerance & Clearance
--Calculate forces and balances, plan based on needed end result
--QUANTIFY
--Shaping/Machining (you need to actually make things)
--Common tools & techniques?

"...Wait. That lets you read Germanian, right?"

Nod nod!

"So, you won't see me doing nearly as much of the hard part as most people because I'm a Spark and we're ridiculous cheating cheaters who cheat- It's definitely some kind of magic and one resistant to analysis, but it helps if we have real engineering underneath the crazy. But, engineering is fundamentally about understanding the way the world moves, in practical, mathematical ways, and then designing things so that your desired result comes about as the result of perfectly explicable rules. For example, I can tell you almost exactly how long it will take a rock dropped from an arbitrary height to hit the ground, with slight variation because of the air slowing it down. Or, using the same kind of math, just how fast a spring with a known strength and compression will spin- This sawblade." She taps the metal surface gently. "Lotta math, lot of writing things, to do it proper."

Math and writing things are good!

Waltana will explain basic kinematics, growing steadily more animated- Acceleration, velocity, Azramut the Stubborn's Three Laws of Motion, the force of gravity, and pose a question with accompanying algebraic equations as to how fast one has to leave the ground to leap to the top of a 100 foot cliff. What about jumping across a 100 foot gap, assuming you launch at the same vertical and horizontal speed (I.E. a 45-degree angle)?

"And while you think about that, I'd be obliged to be about the chamberpot and then that cleaning spell."

Belmarniss points out the chamberpot, casts Prestidigitation to have it about for later, and fiddles with the math while her back is politely turned.