Blue light (pyrotechnic signal)

Blue light (pyrotechnic signal)

Blue light is an archaic signal, the progenitor of modern pyrotechnic flares. Blue light consists of a loose, chemical composition burned in an open, hand-held hemispherical wooden cup, and so is more akin to the flashpan signals of the Admiral Nelson era than the modern, encased signal flares, often launched by mortar or rifle and suspended by parachute.