"Roman candle" is the traditional name for a firework that has been around for centuries. In its simplest form, it's just a card tube with a shell sitting inside it. The fuse runs into the tube and ignites a lifting charge, popping the shell out of the open top and into the air, where it then explodes with its effect. The candle itself remains on the ground.

One of the best known roman candles of all is the airbomb which is a small card tube with one or two shells inside that simply bang when they reach the right height. Some glow with a nice colour too! Enjoyed for generations, these "pocket money fireworks" were becoming misused in the UK and have now been withdrawn from sale.

Airbombs have to some extent been replaced by one or two shot candles with a quieter effect in them such as a pretty burst of coloured stars.

Here, a number of shots (typically 8, 10 or 12) are stacked on top of each other in a single tube. The fuse burns down the tube, igniting each one in turn. A characteristic of this type of firework is the pregnant pause between each shot as the fuse burns down.

As with cakes, it is the bore size (the inner width of the tube) that determines the power of the effect, not the price. Bore sizes are legally limited to a maximum of 30mm and candles with this bore size can produce very big, high breaking effects. Each shot also leaves the tube with a large shotgun like blast.

There is an almost infinite variety of effects available, limited only by the imagination of the manufacturer. However the inherent drawback with single candles is that pause between each shot. To overcome this, manufacturers use one tube per shot, and bundle the tubes together; the firework then becomes a cake and the fuse can be timed to fire the shots at any speed.

Where a candle fires bright shots with a tail which don't explode in the air, this is known as a comet candle.

The principle advantage of big candles is that they can be angled and fanned as required. However, this advantage has recently been eroded by the vast number of quality fan cakes available. Here the tubes are pre-fanned and a cake is easier and more stable to set up (and the timing is spot on).

As a result, the number of roman candles available has dropped and candles are significantly outnumbered by cakes in retailers' ranges.

Most people wrongly assume that to achieve aerial effects in a display you need roman candles. This is probably because the term "roman candle" is so well known whereas few beginners know what a cake is. The truth is that cakes are really just many roman candles bundled together. Unless you have a particular reason not to, you should concentrate your budget on cakes, rather than single candles. They offer a wider variety of effects, better pace and in many cases better value per shot.

The exception to this is the candle barrage which does offer something a little different for larger displays, we'll look at this next.

To overcome the pauses found in single candles, candle barrages contain a number of candles all fused together. Firing pretty much all at the same time the result is a concentrated barrage of effects. Be aware however that many candle barrages contain a large number of small bore candles, so although there is lots going on, the shots themselves are quite small.

This type of firework is also known as a candle battery or candle pot. Although they do offer saturated effects, pace is often erratic because each candle is firing independently. Another disadvantage is that unlike a cake, candle barrages cannot be fused to give a definite ending, and most just peter out towards the end. You can see what we mean by comparing video clips of candle barrages and cakes in our review sections.

Here a number of bigger bore candles (typically three) are mounted on a timber frame with the outer candles angled to fire shots slightly to the left or right. A fuse connects them all, so when you light the main fuse all the candles start together.

Fans have the potential to create some of the most spectacular effects because you get the benefits of the large bore shells and an angled delivery. The downside is they can be expensive. You are paying extra for the timber, fusing, and labour to put them together (members of the public should not try and fuse their own fans). Timing is also a problem because the candles are independent of each other; after the first few shots it is not uncommon for them to get out of synch.

Fan cakes offer all the advantages of candle fans but better timing because each shot is in its own tube and a fuse connects them all. Thus each bank fires in perfect timing.

Overall then, you should only consider candle fans if you have a big budget display. Otherwise, stick to fan cakes if you want this type of effect.