Vintage Bulb

When my dad passed in his 90s i found this in his stuff,he had wrapped it in some really old brown paper then he cut the bottom Off an old bleach bottle and taped it inside....there it sat under the work bench for long as i can remember,it still works and measures 8 inches tall and 4 inches wide at the bulb part,there are no markings anywhere that i can find even with the magnifying glass,would anyone be able to guesstimate the age of this baby? Thank you for looking! Slotman