Flare

FLARE. The term flare in pyrotechny is applied either to coloured fire composition burnt in a loose heap, or to a similar composition charged into a rolled paper case, thus ensuring longer and more regular burning. Flares are used in pyrotechnic displays for the illumination of the surroundings and in a suitable setting, such as a background of trees and foliage, rocks or old buildings. With expert arrangement most beautiful effects are to be achieved, particularly where flares charged with varying composition are used, producing changing and blending colouring.

The flare, or light, in its present form can claim no greater antiq uity than the early part of last century, when the introduction of chlorate of potash permitted the development of genuine colour composition. (See FIREWORKS : Coloured Fire.) Previous to this the only colour achieved, in addition to flame colour, had been the bluish-white light produced by a mixture of sulphur, saltpetre and orpiment. These blue lights, as they were called, were and still are much used at sea for signalling and illuminating purposes. They were also known as Bengal lights, no doubt because Bengal was the chief source of supply of saltpetre.

Signal Flares and Lights.

The introduction of colours which could readily be recognized at a considerable distance opened up a much wider field for the use of flares at sea, and from the middle of the 19th century many patents were taken out ; most of these had for their object a means of self ignition. The first of these inventions was that of Robson, who ignited the flare by breaking a small hollow bead containing sulphuric acid which came into contact with a pellet of chlorate of potash. Subsequent inven tions provided for ignition on the same principle as the modern safety match, and for the waterproofing of the surface, enabling the flare to be ignited in rough weather. Lights of this kind are generally fitted with a wooden handle, in, or to which is secured the means of igni tion. The use of pyrotechnic signals for recognition purposes at sea suggested the Coston light, patented in 1859—a flare charged with layers of composition of varying colours. An invention which has proved of great value at sea is the Holmes light, a device by which a lifebuoy fitted with a flare is automatically launched and the flare ignited on the alarm being given.

The introduction of wireless telegraphy has, to a great extent, rendered recognition signals obsolete, but large quantities of flares are still used by the fishing fleets and by the lifeboat and coast-guard services.

Ships' lifeboats are compelled to carry a supply of red friction ignition lights by British Board of Trade regulations.

During the World War flares and lights of many kinds were designed for signalling and illuminating purposes, the largest ever made being the Dover flares, designed by the late Wing commander Brock, for use on the anti-submarine defences in the English channel, the complete flare being aft. in length, Bin. in diameter and weighing 90 lb., giving a light estimated at one mil lion candle power. The smallest is that fired from a pistol by the infantryman to illuminate the ground in front. (A. ST. H. B.)