A dish lamp is a shallow fireproof dish filled with oil or melted fat, with a wick laid across the rim so one end sits in the fuel and the other hangs over the edge. It takes about 30 seconds to build and gives light the same night, but it spills easily, the wick slides around and it smokes more than an enclosed lamp.
Part of Oil Lamp Construction
The oldest lamp is a shallow fireproof dish of fuel with a wick over the rim. It needs no tools, but the open fuel spills easily and burns smokier than an enclosed lamp.
It Works Because Nothing Else Is Needed
The whole build takes about 30 seconds. The overview lists the steps:
- Any shallow, fireproof dish: ceramic, stone, a metal shell casing or a tin lid.
- Fill it with oil or melted fat.
- Lay the wick across the edge so one end is submerged in the fuel and the other hangs over the rim.
- Light the overhanging end.
What You Need
- A non-porous dish. A ceramic dish, a tin lid or a dense, dry stone. A damp or porous stone can crack when heated.
- A wick. 100% cotton, 1 to 2 cm wide. See Cotton & Plant Fiber Wicks.
- A drip tray. A second, larger dish or plate under the lamp catches spills.
- A small weight (a pebble) to hold the wick end under the fuel.
Fixing The Three Weaknesses
- Sliding wick. Rest the wick in a notch in the rim or pin it under a small stone, so only the tip projects.
- Spills. Place it on a drip tray, in a spot where it will not be knocked, and never carry it lit.
- Smoke. The tip should be small. If smoke trails from the flame, pull the wick back toward the dish or trim it.
Worked Example
A dish holding 60 ml of fat burning at about 25 ml/h (the overview’s figure for tallow at a moderate wick) lasts 60 ml ÷ 25 ml/h = 2.4 hours. Dish size is your capacity; for an evening’s work, use a larger dish or refill after the flame has been out and the dish has cooled.
Common Mistakes
- Overfilling. A brim-full dish slops at the first touch. Fill to where the wick end is covered.
- Using a dish that cracks. Wet stone or thin glass can fail with heat.
- Leaving it near cloth. Curtains and bedding catch from a tipped lamp.
Safety
The most spill-prone lamp
A tipped open dish spreads burning fuel. Smother it with a metal lid, a plate or dry sand or earth; never use water. To put the lamp out, press the wick end under the fuel or cover the flame with a lid; the overview advises against blowing out a fat lamp because it can spatter burning oil. Open flames soot more than enclosed ones; soot is incomplete burning, which makes carbon monoxide. Ventilate with an inlet and an outlet and do not sleep in a closed room with a burning lamp.
What’s Next
- Learn next: Closed Reservoir Lamp — the same idea with a lid
- Combine with: Fire Prevention — what to keep beside any open flame