Dr. Cuthush on the Chinese Fire, &/-€. 



121 



For red Chinese Fire. 



Calibres 

 Pounds. 



12to J5 

 18 to 21 

 24 to 36 



Pulverized Cast iron, No. 1. 



Oz. 



7 

 7 

 8 



dr. 







8 

 



The standard proportion, according to this formula, for 

 rockets of 12 to 15 ponds, is in the ratio of 16 oz. of salt- 

 petre, 3 oz. sulphur, and 4 oz. of charcoal to 7 oz. of 

 cast iron ; and for those of a larger size the quantity of cast 

 iron and charcoal is increased, and for those still larger, the 

 proportion of sulphur, charcoal, and iron is augmented. 

 There are other formulae, however, for the same purpose. 



In the first formula the proportion of the cast iron to the 

 saltpetre is as 7 to 16, 7| to 16, or 8 to 16 ; but in the sec- 

 ond, the quantity is greater, viz. as 12 to 16, and 11^ to 16. 

 Now we may remark, that in the composition for white fire, 

 not only the iron, but the charcoal is much greater, and in 

 the place of sulphur, which is used in the red fire, meal 

 powder is added ^ which bears a greater proportion to the 

 salt-petre than the sulphur in the first formula. These 

 proportions, therefore, are so adapted as to produce a differ- 

 ently coloured flame. When the quantity of iron is con- 

 siderable, with an increase of charcoal, and the addition of 

 gun powder, besides nitre, the fire of the rocket will be 

 white ; but when the quantity of iron is less, and in lieu of 

 meal powder, sulphur is used, the quantity of charcoal be- 

 ing also smaller, the fire will be then red. There are seve- 

 ral methods used to produce red fire, which we shall notice 

 hereafter. In noticing some of the rocket compositions, it 

 will be seen, that the ingredients themselves vary ; and in 

 that description of rocket, denominated the honorary rock- 



Vol. VII.~No. I. 16 



