A source of light consisting of a resevoir, a wick and a piece of glass surrounding the flame(globe). The wick soaks oil up from the resavoir and burns. It's like a big glass candle. This is how people used to light their homes.

The proper way to put out an oil lamp is NOT to lift the glass and blow out the flame. I learned this the hard way. Unfortunately I already had it in my hand way up in the air before I realised it was hot. REALLY HOT. This presented a dilemma, tough it out and put it down gently, or drop it and have shards of hot glass all over the floor.