LOL! It's the butt end of a radiator. :D
Notice the distance from the table to the wall (1) as well as the distance from the chair to the wall (3). Now notice that the chair is slightly behind the table (2).
I have shown this layout here and marked the Radiator (A), Table (B) and Chair (C)
I believe the layout of this particular room is that table is up against an outside wall as evidenced by the lighting in the second photograph (which is most likely the reason several photos were taken from the same vantage point. Good lighting) . Again, judging from the lighting patterns it appears that the photographer is standing in an open doorway.
I the chair is most likely in that particular location for 3 possible reasons.
1. It's warm there
2. The chair hides the radiator.
3. Plenty of light to read by.
Looking at the dimples where the rivets are, I would guess that this particular model was a cheap stamped-metal affair as opposed to the more tradidional cast iron variety. I have never seen a cast iron anything with dimples, but they're quite common on less expensive metals.
I don't know when the practice of stamping metal came into vogue (ww-1 maybe?) but a little research may help you date this photo.
~ Raven ~
PS>> ACK!!! I swear there were not 6 pages of responses when I posted this!! I thought I looked (but then it is 7:00 in the morning and I did just wake up so...)
I thought I had read through all the replies before replying so if I've doubled with someone my apologies (blush)