Assertion: lamp's component | /r/HasProperty | manufactured glass tubing
Facets:
value: economically
type: MANNER
Source sentences:
text: Decades of invention and development had provided the key components of fluorescent lamps: economically manufactured glass tubing, inert gases for filling the tubes, electrical ballasts, long-lasting electrodes, mercury vapor as a source of luminescence, effective means of producing a reliable electrical discharge, and fluorescent coatings that could be energized by ultraviolet light.