Nytmare
David Jose
Rainfall is exactly that. Put out something that collects water and see how many inches of water you end up with. There are some minor complications due to airflow, environment, and level, but that's what it's measuring.One thing that always perplexed me was how rainfall is measured. I remember reading the FR boxed set the Lands of Intrigue and IDR whether it was the Amn or Tethyr book but they said country "X" receives "Y" inches of rainfall a year. How exactly is that measured? Put a graduated cylinder during any given rainfall and its likely to fill up. I've looked it up and still don't get it. Can you explain it?
It's not going to give you a super accurate measurement, but if you imagine an empty birdbath in a rainstorm, the amount of water that's in it when the rain stops is how much rain you've gotten.