Sarun, Appointee of Rixo, is pacing back and forth in his garden, lost in thought. Around him, the serfs are working the estate; inside, the servants are keeping up the house; his wife is around here somewhere, sitting outside in the cool of the evening with the kids, but he can't hear them, they probably went down to the stream. He is thinking about currency issues; they just keep coming up.
... Do elementals recover magic steadily at a rate, or have a limited capacity? They might be more standardized than humans.
Then in that case you could take all of an elemental's magic (she really needs to do the double-checking that elementals aren't people, at some point), wait one minute, take the magic again, and call that your unit of measure.
(Or one hour. Or one second. What precise unit they pick as a base doesn't matter much, though they probably want to decimalize their larger size-units.)
Here's a very short description of how pendulums work, here's how pendulum clocks work, here's how water clocks work, here's how hourglasses work...
Any other problems they need solved?
She knows how to mitigate it, though; antibiotics, doctors washing their hands (with soap!) implausibly often, and extremely clean working environments. Also a lot of other drugs they don't have the tools to make.
They can also concentrate wine and use that to disinfect surfaces and wounds. But yes, having both people and environments far more clean than you could possibly expect to matter are very important.
You know how some people have worms in their body that take blood from them and make them sick? There are lots of things much much smaller than worms all over that can get into cuts and things and make you sick, too, and she bets that glass mages can see them if they're good enough, or else she can show you how to make devices that can see them. Some of those do useful things inside your body instead of being parasites but have bad effects if they get in the wrong place, but others of them are just very bad and shouldn't get in you. You can kill them with heat, by baking or boiling food, which is one reason why cooked food is so much healthier than raw, or by using something poisonous to them, like alcohol.
... So, actually, alcohol is very mildly poisonous to people for the same reason it's actually meaningfully poisonous to the tiny horrible creatures.
(Also, the alcohol you have is kind of weak for the purpose, she knows how to make much stronger alcohol... oh no, this is going to go very badly, isn't it.) ((Too late, she already said it.))
She successfully tries not to laugh.
... No. They should use the very strong alcohol she will tell them how to make to sterilize cuts they get, and boil or alcohol-sterilize the bandages they put on them. (applying alcohol to open wounds hurts a lot, but they only need to do it until they devise a better substitute, which is on her list of goals.) They should make sure that their food - in particular meat - is cooked through. Doctors should wash their hands really very often. And they should encourage bathing with soap and clean water, to the extent people can afford it.
Use heat or cold to separate out the alcohol from regular wine or beer (by boiling or freezing it). If they boil it, they need to make sure to trap the alcohol instead of letting it escape. Silda will explain how to build some devices to this, it's really not that complicated...
(Though at some point she'll want to get to the state of the city vis-a-vis the international situation and whether there's any crises more urgent than that they're stuck in the Bronze Age.)
Great! Then she wants to find an elemental - preferably the one she ran into earlier? - to ask about just how elementals work. And whether or not they have a crisis to worry about.
"I'm sorry to bother you," says Silda quietly, with a friendly and apologetic smile, "but I wanted to talk to you more about your situation, if you don't mind. I'm from somewhere very far away and I was hoping to learn more about elementals?" Silda will turn on the very-friendly-and-helpful-just-want-to-know-more as high as it can go.
"Can you tell me what it is you want, and what other elementals want, and what it's like to be an elemental?"