What is a naphtha stove?

Search: nafta stove; amber spyglass stove

Why: In The Amber Spyglass (which I am listening to on audiobook):

Behind him, just beyond the point where the sunlight reached, Mrs. Coulter was heating some water in a small pan over a naphtha stove. Her daemon uttered a warning murmur and Mrs. Coulter looked up.

Answer: Naphtha is "a class of colorless, volatile, flammable liquid hydrocarbon mixtures." Gasoline and kerosene are both technically considered naphthas. The stove might look like this:

Source: Encyclopedia.com, Google Images

The More You Know: Since I was listening (not reading), I first searched for "nafta." Polish people actually do call it nafta. They also say benzyna rektyfikowana.