Thought this might be of interest.
Came across this glass bell shaped item on a local car boot. As it was cheap and without any idea what it was I took it home to do some digging. It's hand blown, showing striations and has a folded rim. It has some age showing signs of wear.
After some research I discovered that it's a smoke deflector for use with oil lamps. The idea being it would be suspended above the oil lamp and help dissipate any smoke and stop staining to the ceiling above the lamp. It's approx 19.5cm tall and 16cm across the base.
I'm thinking Victorian or early 20th Century, if anyone can narrow this time period a bit it would help me.
Had no clue when I first spotted this, its amazing what you come across,
Keith M