Carbide Lamps: the Caver's Friend
29:08
How the gas mantle made lamps 10X brighter
14:06
Wolf Flame Safety Lamp: Many Bright Ideas
31:46
Why do hurricane lanterns look like that?
24:05
Mining Safety Lamps: a Light in Dark Places
20:04
La curieuse relation entre le sel et le pétrole
16:33
The "Impossible Torpedo" was real
22:42
J'ai construit une horloge à tour
13:22