Thunder Flash report

Thunder is the noise caused by the explosion of a composition and which emotionally increases the activity of the firework display. The composition which also produces a flash effect is called Flash thunder  

The flash thunder No.l is a chlorate composition. This is easily ignited and it explodes perfectly even in a relatively small turn of kraft paper without glue or any container, and there is no need for a strong capsule. This kind of composition is therefore most popularly used at present in Japan from the economical standpoint, but it is sensitive to shock and friction, and recently the chlorate has been gradually replaced by perchlorate. 

The single shadowed area shows the medium intensity noise zone and the double shadowed area shows the loudest. With this composition the capsule must be strong enough to explode completely and moreover some device must be made to ignite the composition easily. No. 2 is relatively well ignited and most popularly used. No. 3 gives the loudest noise. 

4 contains neither sulphur nor sulphide and this produces a slightly smaller noise than the first three, but it is the safest of all to handle. 

The constructions of the noise units are shown in Fig.81. During the manufacture of the units, the composition must only be lightly compressed, otherwise it only burns like a toy fountain without explosion, especially with perchlorate compositions. It is best to keep the composition lightly in a capsule to obtain the loudest noise, but this type of noise unit cannot be used as a filler for shells lest it causes an accident.(The 

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Flash Thunder A report accompanied by a strong flash. 

A group of many reports called "ten thousand thunders" create loud reports with strong flash lights. 

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