The principle of a candle is to create a solid stick of a combustible fuel having a low melting point. Many oils can be easily formed into waxes and are ideal for this type of application. A wick is included inside the stick of wax and protrudes from one end so that, when the wick is set alight, the flame causes the wax to melt and this, in turn, provides more fuel to keep the candle burning. As more was melts, the fuel soaks into the wick and is drawn towards the flame by capillary action, where it is converted into hot gases and light by the combustion process. Candles were undoubtedly used in many, many situations, most probably in small lamps used as harbour lights. Obviously, the low intensity of the light created by candles precluded their use in many major lighthouses, although it is surprising to note that Smeaton used the light from a mere twenty-four candles in his famous Eddystone lighthouse. The arrangement he used was similar to the one shown below.