The Thallium-Mercury HID Lamp - a Light Source for Light Communities and Areas of Light
Depiction of a possible appearance of
the Thallium-Mercury HID lamp
According to Dr. Larson the light was predominately green. During an interview conducted when I collected this experimental lamp, he noted: "I thought it would be a great lamp for lighting in the parks and stuff like that because it was 85 lumens per watt, and green."
~ Hal Wallace ~
"In 1941, Schnetzler made a mercury-thallium lamp having an efficiency of 70 lm/W, almost twice as high as its mercury counterpart. The desired thallium vapor pressure was reached by operating the arc tube at thrice its normal power loading, with the consequence we can imagine on the life expectancy."
High-pressure metal-vapor electric discharge lamp:
High-pressure metallic vapor discharge lamp including mercury and thallium iodide: https://patents.google.com/patent/US3431447
Cobra's up to date post: http://2012portal.blogspot.com/2018/08/dream-of-dolphin.html