The metal chimney above the wick is 5" high, 3" in diameter, and in a shape that is two cones with the bases attached in the middle and the ends cut off and open. It's kind of a cylinder but wider in the middle than at the ends. Both ends are open. In the bottom half of the chimney is one small opening 1" in diameter that is covered by a mica window. The only openings in the chimney above the wick are the open end at the top of the chimney and the small mica window. There is a hinge on the chimney so that it can be tilted back to see the wick. All is painted black.
I'm not sure if my descriptive powers are adequate, but does anyone know what this might have been used for? Thanks for any help you might provide!