Al Cart : - Not really all that old the design falls into place about the time of the launching of the Titanic -notice the major use of rivets to make an
air (and smoke ) type fittings - tho it probably was being produced as late as the 1930s-
The idea was to allow the hot exhaust gases to rise up inside the Curved crescent part stratify and as they cooled only the coolest would fall down
to the smoke pipe hole and exit via the chimney, This also had a tendency to reduce smoke back when the '' Wind was blowing from the wrong
direction
Originally the whole thing wood
have had a sheet metal shell around it (thinK stovepipe grade ) and hundreds of thousands were also equipped
with a blower cabinet containing a Squirrel Cage fan to warm distant rooms via attached warm air ductwork ( and cold air returns )
I have a pre world war 11 model setting in my basement that went thru a conversion process to make it a Fossil Fuel Fired Forced-air Furnace -
probably 50 years ago !
This is a back-up to my back-up to my plan to go south for the winter !
For the Good of the Crafts ! Big AL