Whistling fireworks

In forming whistling fireworks, the aromatic compounds described above are mixed with oxidisers such as potassium nitrate or potassium perchlorate and pressed into tubes. On combustion, a loud whistling sound is produced, whose pitch is related to the length and diameter of the tube. 

The peculiar property of potasMum piarate to whistle wlule burning has been known for a long time suid has been made use of for producing the amusing whistling fireworks. To make this article ... 

Aspects of special effects described in this chapter include fuses (quickmatch and plastic fuse), lances (small coloured flares), set-pieces and devices (assemblies consisting of various types of fireworks linked together), flash, bang and whistle compositions and daylight fireworks (smoke puffs and coloured smokes). Finally, the electrical firing of firework displays is discussed. 

Two basic audible effects are produced by explosive and pyrotechnic devices a loud explosive noise (called a "report" or "salute" in the fireworks industry) and a whistling sound. 

Whistles, Pyrotechnic. US projectile ground-burst and booby-trap flash simulators precede their flash and expin with a whistling sound. The fact that certain compns whistle when compressed into a tube and ignited has been used in the fireworks industry for many years. The active substance most often used in pyrot whistles is gallic acid (3,4,5-trihydroxybenzoic acid). The K salts of benzoic acid of 2,4-dinitrophenol and of picric acid (2,4,6-trinitrophenol) and the Na salt of salicylic acid (o-hydroxybenzoic acid) are also effective. They are combined with K chlorate,... 

We have five kinds of sounds shooting and explosive sound, thunder report, whistle. and humming. When we arrange these sounds at proper time intervals, e.g. of 2 or seconds in the case of 6 inch shells, we can make the sounds into a rhythm to create firework music. In this case, the first three sounds play the role of percussion instruments. But to bring the five sounds into music, the time of ignition, delay, explosion and the period of the whistles and hummers must be accurately controlled.(See ). 

It is soluble in water or alcohol. This is a raw material for blue-black ink, but for fireworks it is used in combination with potassium chlorate as a whistle composition, which is quite sensitive to shock and friction. 

Materials and labour enter into the left(debit) side and come out of the right(credit) side as finished goods. Practically energies like power or heat and the loss of tools, furniture, fixtures and structures should be added to the left side, but these are quite small in firework manufacture-The operations which move the left side elements to the right are almost all physical and are seldom chemical. For example, the manufacture of potassium picrate as the material for whistles or the nitration of pitch for black snakes belong to the chemical operation. 

J. Domanico, G.V. Tracy, M.N. Gerber, Frequency Components of Pyrotechnic Whistles , Proceedings of the International Symposium on Fireworks, 1994. 

WHISTLER A firework designed to whistle by virtue of an explosive composition containing gallic acid or similar. 

Two basic audible effects are produced by pyrotechnic devices a loud explosive noise and a whistling sound. In the terminology for noise effects, the sound effect itself is a report. The device that prodnces a report in the fireworks industry is a salute, and in the military it is a simulator. The typical composition used to produce a report, whether in civilian or military applications, is an oxidizer-metal mixture that is termed a flash powder. 

Devices producing a whistle-like effect have since found uses both in the civilian arena for fireworks effects and in military applications for simulators used in training exercises to simulate incoming rounds. Titanium particles (in particle sizes greater than 100 mesh) can be added in low (5% or so) amounts to a whistle composition to produce a spark effect to accompany the audible output. 

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