It looks like a slug iron,not for ironing slugs but hollow with a door at the back [this one]. You heat up an iron slug and put it inside and close the door, that way you don't get smoke smuts from the fire on the iron, plus you can have several slugs so don't have to stop ironing to wait for the iron to heat up. The add on is a later embellishment, the reason the pipe sticks up inside the cup is because of the nut on the threaded pipe.