A betty lamp is a small enclosed metal reservoir shaped like a gravy boat, roughly 10 cm long, 5 cm wide and 4 cm deep, with a wick channel at the spout and a hinged cover, hung from a hook or chain at eye level. A cruise lamp nests two of them so that the lower one catches fuel dripping from the upper. Both are spill-resistant and burn any lamp fuel.
Part of Oil Lamp Construction
The betty lamp is an enclosed metal boat with a wick channel at the spout, used for centuries in pre-industrial Europe and America. It is spill-resistant, burns any lamp fuel and hangs at eye level.
A Hanging Boat Puts The Light Where The Work Is
The overview calls the betty lamp one of the most practical survival lamp designs: enclosed (spill-resistant), able to use any fuel, and hung at eye level for work light. The cruise lamp is two nested betty lamps; it is cleaner, but more complex to build.
Method: Building A Betty Lamp From Scrap Metal
Step 1: Form the boat. Shape a small boat from sheet steel, copper or tin. Roughly 10 cm long, 5 cm wide, 4 cm deep.
Step 2: Crimp the spout. Pinch one end into a narrow channel for the wick. The wick lies in the channel with its tip just past the end.
Step 3: Add a hinged cover. Make it from a second piece of metal. It reduces evaporation.
Step 4: Add a hanging point. Attach a wire hook or chain.
Step 5: Fit a flat wick. A flat cotton wick lies in the channel with one end in the fuel. See Braided vs Twisted Wicks.
Cut sheet metal with gloves on and file down every edge before assembly.
Worked Example
The bounding volume is 10 cm × 5 cm × 4 cm = 200 cm³ = 200 ml. A boat shape holds less than the box around it, so 200 ml is an upper limit. At the overview’s 25 ml/h for tallow, 200 ml ÷ 25 ml/h = 8 hours at most.
Common Mistakes
- Letting the spout channel loosen. The wick slides out. Crimp snugly.
- Hanging it under combustible material. Heat and flame rise. Keep clear space above and behind the lamp.
- Hanging from a thin string. Burning through the string drops the lamp. Use wire or chain.
Safety
A swinging lamp is a falling fire
A hung lamp can swing into a wall or drop if its hook fails. Hang it from a solid support, away from cloth and timber. The metal gets hot; use the hook or chain to move it, only when out and cool. If fuel ignites, smother it with the cover, a plate or dry sand or earth; never water. A smoking flame is incomplete burning and makes carbon monoxide; ventilate with an inlet and an outlet.
What’s Next
- Learn next: Tin Can Lamp — a simpler metal build
- Combine with: Reflectors — direct a hung lamp’s light onto the work