Vintage mercury vapour discharge lamps with E40 GES screw caps. Old or retro lightbulbs. Retro. Steampunk, High pressure mercury, medium pressure Stock Photo - Alamy
Small Public Water System Technology Guide - UV Disinfection Educational Module
GEC / Osram 400W MA/V medium pressure mercury vapour lamp, an early example of mercury lamp. Made in the UK Stock Photo - Alamy
Vintage mercury vapour discharge lamps with E40 GES screw caps. Old or retro lightbulbs. Retro. Steampunk. High pressure mercury, medium pressure Stock Photo - Alamy