Chrysanthemum shells

The description here particularly refers to the bursting charge of the chrysanthemum shell which are called V/arimono in Japan. A different bursting charge is used for the other kind of shell called "Poka which simply uses black powder grains. 

Compositions for chrysanthemum shells(Warimono) must be selected with special care, but for Poka the selection is not as serious as for Warimono. 

For example in the manufacture of round stars or paper pasting the outside of chrysanthemum shells. This may be characteristic to firework manufacture and quite laborious. The half-finished pieces are apt to be accumulated in workrooms and the stagnation of the flow of the compositions is enlarged. 

A black fine powder which has a somewhat hygroscopic feeling. The apparent specific gravity is 0.22g/cc. The dye adsorption power is the largest of all the kinds of plant coal. A mixture of hemp coal, sulphur and potassium nitrate burns to produce a violet flame and less fire dust than pine charcoal. It is used to obtain a large force of explosion as a component of black powder or in combination with potassium chlorate or perchlorate for the bursting charge of chrysanthemum shells. 

Chrysanthemum Shells (translated from Japanese), 2003 [ISBN 1-889526-14-2]. 

Figure 4.6 Red chrysanthemum and silver wave shells. (Courtesy of Pains Fireworks Ltd.)...

A shell ascends displaying some small effects thunders, small flowers, smoke etc. one after another on the trajectory. When the shell reaches the maximum height, it displays a round chrysanthemum flower the colour of the flower changes from one effect to another. When the flower goes out, a flare of bright light remains. 

Amber Chrysanthemum vith Small Flowers in Relief and vith Kyokudo of Ascending Small Flowers The shell ascends displaying small flowers on the trajectory and at the maximum height explodes into a large amber ... 

In this table "Large" is used for Poka and "Small" for Warimono (Chrysanthemum). Warimono is manufactured by pasting many layers of paper on the sphere and the completed shell has a thicker wall than that of Poka. It is necessary to manufacture both Poka and V/arimono with the same external diameter since they are both used in the same size of mortar. 

Pasting is peculiar to Japanese firework manufacture. Stars are allowed to grow into a spherical shape by sprinkling the powder of a composition on to core grains. This process is popularly applied for the manufacture of colour changing stars used for the Warimono shells Chrysanthemum. In Japan maximum effort is made in the production of stars of this kind. 

Warimono is a shell which displays a flower like a chrysanthemum in the sky. The stars stretch out to form a round flower. The duration of the flower is generally 2 seconds. 

The representative method of assembly for a double petalled chrysanthemum is as follows First plan the inside spheres. This depends upon the individual plan, but in general the diameter of the middle sphere (Dm) is equal to about a half of the internal diameter of the shell(Di), and that of the centre sphere Dc about 1/k of Di. The size of each star in the middle sphere is equal to about half the size of the main star the size of tlie contro star is about 1/ f that of the main star. There are... 

A large chrysanthemum developes in the sky and then small flowers appear on the chrysanthemum(Fig.115.(C)). With another type the small flowers appear only after the big chrysanthemum has been extinguished. This is achieved by using somewhat longer fuses for the small flowers. These varieties are only successful when the size of the shell is large enough to contain many small flowers, i.e. 9.5 inches or more. 

Bottom explosion. (See "No lift.) This is an accident where a shell explodes in the mortar without ascending. This generally occurs when the lifting charge is missed and the igniter, a Sindoro, is thrown into the mortar. If it is a report shell or chrysanthemum the mortar is broken into pieces, and it is quite dangerous. However if it is a quick firing shell such an accident does not occur. 

The diameter of a firework flower(chrysanthemum) depends mainly upon the nature of the bursting charge and the paper pasting on the shell, i.e. the strength of the sphere. 

Kind of shell (inch) Weight of lifting charge (g) Altitude of explosion (ra) Diameter of chrysanthemum (m) V. eight of shell (g)... 

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