Candles have been used as sources of light for thousands of years. The ways in which these candles have been made has differed greatly over time. There has also been a wide variety of different ways in which candles have been fuelled and also a wide variety of different uses for candles. The humble candle has become a multi use item with thousands of benefits that go well beyond the initial use - to produce light.

The candle's other primary function has been to provide heat and many versions of candles have been developed to maximise the heat output. Candles have been around for a long time and in this time they have been used in religious ceremonies and also for timekeeping as well as for decoration, for air freshening and also for adorning a birthday cake.

The products used to create candles are different all over the world and throughout time candles have been made out of different substances. Candles that were made in the early parts of the 19th century were made from beef fat rendering known as tallow. The modern candles are more commonly made from wax. There are many different types of wax including gel, soy and beeswax but the most predominant type of wax is paraffin.

Candles are typically made with a wick that is lit. This wick is covered in wax which melts and vaporises. This vaporised wax provides fuel to the fire and keeps the flame burning. This encourages the candle to burn slowly and last for a long time. The process is also beneficial as it is self sustaining and does not require the person to monitor the candle or relight it.

As the flame warms the wax into vapour it works slowly down the candle and slowly uses up the wax. This is an efficient method that makes candles last longer. The science behind the burning of a candle helps us understand the processes that go on when a candle burns. In the area of the candle that burns blue a reaction is taking place in which the hydrogen is being separated from the wax and is burning. This process results in water vapour. The yellowy section of the flame occurs as a result of the oxidisation process that sees carbon dioxide being created from the carbon.

The position of the wick as these processes take place is very important to the time in which the wax is fuelled. One way to slow the rate at which the wax is used up is to reduce the length of the wick. The shorter the length of the wick that is exposed the longer the candle will last. Many people often decide to cut their candle wicks short manually with scissors to lengthen the life span of their candles. There are even special instruments called wick trimmers that are designed to make this task easier.

There is evidence of candles that were in use in Roman times. At this period of time many candles were made from the animal fat residues and the long pith found in a rush. Beeswax was used as a fuel by the Egyptians and many of their candles date back over 3000 years. By the 18th century was much more common for the fuel to be extracted from the oil taken from sperm whales.