Museum of Curiosities, Hackney

[ppppenguin]

It's lovely, whatever it's called.

This page suggests that a Geissler tube is normally sealed off:
http://physics.kenyon.edu/EarlyApparatus...c_Egg.html

The whole site is rather nice too: http://physics.kenyon.edu/EarlyApparatus...icity.html

It would have been powered from some kind of electrostatic machine such as a Wimshurst.