Minimoog
Enlightened
- Joined
- Jan 13, 2005
- Messages
- 771
I have been doing a bit of research and amazingly I can't find anything out at all. I was trying to find out about torch bulb design and how it evolved from the first electric torch up until the coiled filament type - so late 1800's to the 1930's. Really not much out there for torch bulbs...
Looking in old (1903) adverts I see that bulbs are drawn with a small twist on the top - where the envelope was formed - but I have never seen one of those in person or even a photo. Later in around 1908 there was mention of an improved design bulb in the adverts. Early ones may have been carbon?
The bulbs I have from 1910-1920 period are all finished like a small rugby ball - the glass envelope is squashed. Sometimes there is a white glass section directly behind the filament to help the light escape forwards and not be absorbed in the body of the bulb. The bulb I have from the 1913 period (made in Germany) really is pretty dim - more of a glow - as the batteries of the time were very weak.
Usually the older bulbs have the filament in an S shape or sometimes a loose U which goes across the bulb. When using these bulbs the beam is diffuse as the illuminated area in the reflector is much larger than the normal coiled wire.
So if you could check your older torches and see if any interesting old bulbs reside within and share them here that would be very interesting I think.
Looking in old (1903) adverts I see that bulbs are drawn with a small twist on the top - where the envelope was formed - but I have never seen one of those in person or even a photo. Later in around 1908 there was mention of an improved design bulb in the adverts. Early ones may have been carbon?
The bulbs I have from 1910-1920 period are all finished like a small rugby ball - the glass envelope is squashed. Sometimes there is a white glass section directly behind the filament to help the light escape forwards and not be absorbed in the body of the bulb. The bulb I have from the 1913 period (made in Germany) really is pretty dim - more of a glow - as the batteries of the time were very weak.
Usually the older bulbs have the filament in an S shape or sometimes a loose U which goes across the bulb. When using these bulbs the beam is diffuse as the illuminated area in the reflector is much larger than the normal coiled wire.
So if you could check your older torches and see if any interesting old bulbs reside within and share them here that would be very interesting I think.
