The meaning of “eternally burning black pipes”refers to the physical looking and especifically the faces of the firemen involved in the story.
It implies the colour of cinders and ash about them, and the continual smell of burning from their pipes. In this regard, the story describes a fireman having black hair, black brows, a fiery face, and a blue-steel shaved and unshaved look. These men were all mirror-images of the main character that the autor wants readers to know through his looks as well as his proclivities.
