What kind of pan is this? (photo) How would you use it?
It looks possible that the two pieces don't actually go together. The patent referred to is number 625702, for an enameled chafing dish with a domed lid. (It's kind of hard to tell, but I think the innovation being claimed is the lip/indentation which allows the handle to be attached without damaging the enamel.)



The patent does mention the inventor's desire to apply the patent to other dishes, not just ones of the chafing variety, but the enameled piece you have greatly resembles the enameled portion of the dish in the patent drawing.