carbon arc lights were commonly used in projetors and theater spotlights for many years. The carbon rods burn with a bright light and create smoke that has to be vented.

I'm *very* glad these are something far more benign than what I was envisioning: those horrible horizontal cages that lunatics were locked into back in the 1800s. Something like that can be seen in the film "Bram Stoker's Dracula", and others in the film "Amadeus".

poetic image - lovely

What a *great* image!