1. One of the earliest types of central heating was an "octopus" system that allowed heat to simply rise with gravity from a coal fire in the cellar via ducting to floor grates in various rooms. The galvanized ducting in your picture sort of resembles this. However, I don't believe such a system was still in use in 1906, but I could be wrong.

2. The ducting can't be used for a gas flue. The gas fire needs outside combustion air for starters. I don't think the ducting is large enough to use as a chase either for the flexible liner one uses for gas appliances.

3. Why it is connected to the fireplace is a mystery, however. And a little scary.

4. We found a good use for some of ours: A chase for running new electric and other cables between floors!

In 1902 fireplaces were more a necessity and not considered particularly attractive. Hence I think it quite doubtful that a faux fireplace was originally installed. Look for more clues!

Thanks Clarion - good idea about using it as a chase. There's no sign of this ever being part of an octopus system, and I guess it's unlikely since the duct/flue was definitely running up from the fireplace. The only other clue in the fireplace is a little plug in the floor - possibly where a gas line ran?

Here's what the fireplace looks like - pretty decorative, really.

It definitely looks like it was for a small gas heater, probably with ceramic blocks which glowed a nice red.

Why Clarion said a gas fireplace needs outside air for combustion is beyond me--modern high-efficiency ones might, but certainly not ones from the turn of the century! My gas insert (now looks like logs, originally ceramic blocks) uses room air and vents up the old, tile-lined flue, and has since the house was new in 1908. An old house is just not sealed enough to necessitate using outside air for a fireplace of the old type.

As for them not being decorative--in a sense not many were put in just for looks--they were indeed a necessity if you didn't have central heating--but many old houses have fireplaces with nice green or white mottled tile surrounding a metal front, and topped with a very handsome wooden mantle...as my house has. It even has a bevelled glass mirror and an upper shelf supported on round columns with egg-and-dart moldings!

Until you measure, you won't know if a flexible liner could be inserted, or you could replace it with a new double-walled one.

Interesting info, columbusguy. If yours dates to 1908, I'm guessing that's what was here. It's off in a corner of the house, so I hope it's not the only thing they had for heat!

I kind of like the idea of putting a new gas burner in there, but it does seem like a very small space if the vent needs to be double walled. The outside of the galvanized chase is only 3.5" x 3.75".

I'm not sure, but I think the double-walled flues are about six inches--you might check that. What you can do is put in the new flue, then box it in so that it looks like an old masonry chimney breast.

It took me a while to find gas logs which fit my firebox--finally found a set on sale at a gas fireplace shop--it had to be no wider than 18" since the side walls were angled in toward the back!

I've seen the old burners on ebay, make sure they are complete with the ceramic blocks, since those are the hardest to find.