Definition
A roman candle is a cardboard tube that fires a series of projectiles one after another: stars, comets, small bombettes, whistles or crackling. Each shot is separated from the next by a layer of delay composition, which produces the characteristic steady rhythm. Display candles run from 20 to 60 mm in calibre, with 8 to 20 shots and heights of 20 to 80 m depending on diameter. They are sold singly or bundled into fans and pre-fused batteries. Standing upright they draw columns; angled in crossing pairs they weave the curtains and crossfires that structure a sequence. Small calibres fall into categories F2 and F3, larger ones into F4.
In practice, for the display company
A candle is counted in shots and seconds: its duration sets the length of the sequence it occupies. PyroDesk records shot count, cadence and mounting angle; PyroSimulator replays the exact rhythm of the stars, so a curtain of crossed candles can be judged on screen before it is wired on the firing site.