It is hard to see in the photo due to the amount of dust, but there is a pipe running up from the floor of the hearth (excavated to about 7" below the level of the floor) and up in the chimney-breast wall. I've outlined it in red. It is blocked in the cellar but clearly emerges and combines in the chimney in the room above. I'd love to know what sort of stove would have been in the cellar. I have a fairly good idea of what sort of range would have been in what I've been calling the "dining room". However I guess I should now start calling it the "old kitchen"? It was clearly a kitchen due to the size of the fireplace opening, the height of the opening is obviously meant to take a range for cooking.
House archaeology will continue, but so far I have found an extra fireplace or stove or washing copper, in the cellar, the space for a cooking range in what I thought was the dining room. Did I mention the extra rooms that appear to be under the house? It took about ten large rubble sacks and two trips to the dump to clear this fireplace so I hate to think how many bags and trips to the dump it will take to clear just the first exploratory holes in the supposed filled-in extra rooms in the cellar.
Many thanks to my friend Neil for his help in digging out, and excavating the fireplace.