in our holiday house we still cook on an iron stove. we also installed a small gas burner, because that stove is the heating system for all the 3 small rooms. it gets really hot - so usually you don't want to use it during summer.

but the original pans are out of copper. they have a complex shape so, if you remove the cooking top, you can hang them directly into the fire. cast iron surely was and still is a thing. but i will always choose copper over cast iron for something i want hot quickly. i would bet that most kettles where made out of something thin and conductive, so your water is hot quicker.

all our copper is black from the sud.

Alternatively, shiny kettle and the pot sees its own black reflection in it.

(But yeah, I assumed they're both black/cast iron)