Oil lamps, 1st century BC-1st century AD.

EGYPT - AUGUST 23: These three small pottery oil lamps are approximately 2,000 years old and are probably Egyptian or Romano-Egyptian. Oil was used to fuel the earliest lamps such as the simple ceramic ones shown here. These examples illustrate some of the difficulties in the management of early lamps. On the left, the lamp's oil has been allowed to burn down too low, producing an unpleasant black smoke. The central lamp has a well-matched wick, is two thirds full of oil and is producing a steady flame. The right hand lamp is over-filled with oil and has too fat a wick, producing a less constant flame. (Photo by SSPL/Getty Images)