Erik's link to the orange lamp on Saturday reminded me to post this. This is Project #1 in Making It, and we often open our lectures by building one of these, but I realize I've never talked about oil lamps here on the blog.
Forgive the somewhat atmospheric photo. What you're looking at is the simplest thing in the world: an oyster shell filled with olive oil and balanced in a small dish of sand. Three pieces of cotton string are lying in the oil with their ends poking just a little way off the side of the shell. Those are the wicks.
This is a shell lamp. This is perhaps what the first lamp ever looked like. (A Paleo-lamp?) At the very least, this is a fundamental human technology. When you build one, you're echoing the practices of so many cultures over so much history--from the flat clay oil lamps of Rome to the soapstone lamps of the Inuit to the the ghee-burning temple lamps in India.
Even if you don't buy all this romance, it's a good trick to remember next time you're in a blackout and running out of candles.
One reason I burn little shell lamps like this because I like candlelight, but candles are expensive, especially beeswax candles, which I prefer over petroleum-based candles. Since these lamps use olive oil or any cooking oil for fuel, they're a great way to us up those rancid or off-tasting oils which tend to clutter the back of our cupboards. I save the stale or otherwise suspicious olive oil from my herb-infused oil experiments for this purpose-- oil which I'd have to throw away otherwise. This makes my flame habit essentially free.
The shell lamp FAQ:
- A lamp with a single wick burns approximately 1 tablespoon of oil per hour (burn time varies by wick size and number). You can easily top off the oil as it burns.
- You can use any100% natural fiber for a wick: a bit of string or a shoe lace or a sliver of cotton rag work great. The wider the wick, the wider the flame.
- Want more light? Add more wicks. The shell above has three.
- Yes, you can add a few drops of essential oil for scent.
- Adjust the flame height by lengthening or shortening the wick length. The oil doesn't get hot, so you can just poke your finger in the shell and push the wicks up or down.
- Don't use lamp oil, kerosene, etc. as fuel--only cooking oils. Conversely, don't try to burn cooking oil in other types of oil lamps, like hurricane lamps.
- Stabilize tilting shells either by nesting them in one another or by putting them in little dishes of sand, salt or pebbles. I'm using a couple of oyster shells that I dragged home from an oyster bar right now because I broke my favorite shells, but in terms of restaurant-sourced shells, I prefer big mussel shells because of their depth. Scallop shells work well, too.
- If you don't have a shell, you can use any shallow vessel. A jar lid works especially well if you dent one edge to make a little "V" for the wick to rest on. Lately I've been eyeballing ashtrays in thrift stores, wondering how well the cigarette rests would work as wick rests.
- Like any candle, the open flame can set things on fire, but if you knock one of these over it's not going to erupt into a conflagration of doom. Olive oil and other cooking oils have high flashpoints. All that will happen is that you'll stain your favorite tablecloth. The wick will most likely be snuffed out in the spill. If it doesn't get snuffed out, it will continue burning if it can continue to draw oil from the spill.