Skinny And Ordinary

This is an unexpectedly slender cast-iron column:

The plastic tarps are in a monitor-style skylight above the main roof. The beam on the far left, and the beam at the top of the column are in the plane of the roof. It may look like the column isn’t supporting much, but it has a fair share of the skylight weight as well as roof load from off-camera to the left. Overall, it’s supporting roughly the same load as the columns at the edge of the skylight (like the one behind the ladder) and the ones at the ordinary roof area. It’s a light load by modern standards because the wood framing of the building is lighter than modern fire-rated constriction, but it’s still thousands of pounds.

In any case, that’s a column with a diameter of roughly five inches that’s more than twelve feet high. Slender by any circumstances, but particularly so for cast iron. There are several obvious indicators that it’s cast iron and not a wrought-iron or steel pipe, starting with the fact that it’s not cylindrical. There’s a definite taper from the top to the bottom, as well as maybe (hard to tell by eye) a little bit of entasis. Then there’s the fact that the capital and top connection are integral with the column shaft, as well as what appears top be a pair of unused connections a bit below the capital:

Those unused connections are below the main roof level. Given that the building was constructed as a factory, they may be attachment points for equipment drive shafts.