The article says it's a carbon filament bulb. Modern incandescent bulbs use a tungsten filament. Carbon filament bulbs are still sold for decorative lighting:

The article says it's a carbon filament bulb. Modern incandescent bulbs use a tungsten filament. Carbon filament bulbs are still sold for decorative lighting: https://www.amazon.com/carbon-filament-bulb/s?k=carbon+filament+bulb https://www.amazon.com/carbon-filament-bulb/s?k=carbon+filam... Kind of related: an interesting video on how tungsten filaments are made: https://www.youtube.com/watch?v=DIGqBb3iZPo https://www.youtube.com/watch?v=DIGqBb3iZPo