222 



PYROTECHNY. 



Pyrotech- flame. It is both useless and expensive. The flame 

 "y- which it gives is not perceptible in the burning com- 



s< "V^^" pound ; and a true white flame can be procured only 

 by means of zinc, as we shall hereafter see. 



Glass. GLASS. Pounded glass is recommended in some re- 



ceipts for producing red sparks. It is not orjly, how- 

 ever, useless for this purpose, but is a dangerous in- 

 gredient in driving, as it is hard enough to set the 

 compositions on fire in the hands of the workmen : 

 while red sparks, or red fire, as it is called, is produced 

 in a more perfect manner by charcoal. It is very 

 necessary, and full time, that many of these absurd 

 processes should be simplified. 



Mica. MICA. Mica in scales, as it is often found among 



decomposed granite, is also recommended for produc- 

 ing what is called red and yellow rain ; but there are 

 no virtues in yellow or brown mica more than in other 

 colours, as is asserted in the receipt books. The fire 

 which it produces is distinguishable from that of char- 

 coal, but that only at very small distances ; and as it 

 is an expensive or difficult substance to procure, it may 

 in almost all cases be safely omitted. 



Iron. . IRON. This metal is the chief ornamental ingredient 

 in pyrotechny, from the property which it has of burn- 

 ing with brilliant sparks when highly heated. It is 

 the soul of Gerbes, and is introduced into all fiery 

 showers. But the effects of different kinds of iron dif- 

 fer much, and it is important to distinguish them for 

 use. It is common to recommend iron filings for most 

 works, particularly for the smaller ones. But malleable 

 iron is far less combustible than steel or cast iron ; or 

 the carburetted varieties yield the most sparks, and the 

 finest light. Hence if filings are required, as is the 

 case for the small wheels and other similar works, they 

 should be those of steel at least, as there are not many 

 varieties of cast iron that are easily filed. But in the 

 larger works, it is necessary that the iron should be in 

 particles somewhat larger than it can be procured by 

 means of any file in common use. It is therefore re- 

 commended to pound it in a mortar, a thing which is 

 scarcely practicable in any species of iron. It is more 

 easy to procure particles of the requisite bulk by pound- 

 ing iron turnings ; the thickness of which is easily re- 

 gulated, and which are indeed to be procured abund- 

 antly in all iron manufactories. There are two advan- 

 tages in the use of Jarge particles, as they can longer 

 be preserved from rusting in the case, and as they 

 yield, in burning, much more complicated sparks. Cast 

 iron is also in itself less liable to rust than malleable, 

 and hence it is attended with another advantage. We 

 may add that the best iron for this purpose is what is 

 technically called black pig ; very distinguishable, from 

 its dark gray colour, as it is the most highly carbuvetted 

 variety. White pig has the advantage of being more 

 brittle ; but if this be more easy to pound, it is more 

 hard to turn. We may add, that it is possible to di- 

 minish the tendency of iron to rust when thus used, by 

 means of lac varnish. 



. Antimony. ANTIMONY. This metal is largely used in fireworks 

 for the production of blue light. It is a mistake to 

 suppose that this cnn be done by means of sulphur, as 

 when this substance burns rapidly its light is white. 

 Whether the sulphuret of antimony or metallic anti- 

 mony is used, in both cases it is the burning of the 

 metal which produces the colour. The sulphuret. com- 

 monly called antimony, is used for the stars of rockets 

 and common blue fires, but the light which it yields is 

 not so blue or clear as that from the regulus or me - 

 tallic antimony. This therefore is introduced into the 



compositions for small ornamental or figured lights, Pyrotech- 

 commonly called speckies. In all cases antimony must y- 

 be powdered ; but it need not be extremely fine ex- V >**Y* / 

 cept for the last purpose. 



ORPIMENT, RED. This compound of arsenic and Red orpi- 

 sulphur is chiefly used for producing the 'hite colour tnent. 

 in signal lights, commonly known by the name of Ben- 

 gal lights, and used either for military purposes, or in 

 surveying, or lastly in ornamental fires. The light 

 which it gives, though white, and accompanied by 

 much smoke, is not nearly so bright as that produced 

 from zinc ; while it is extremely poisonous wherever 

 the operators are exposed to the smoke or burning. 

 For these two reasons its use ought to be exploded al- 

 together. 



ZINC. The use of this beautiful ingredient is scarce- Zinc, 

 ly known to any of the pyrotechnists, although as a 

 substance for light, it is far superior to any of the m- 

 tals. The light which it yields on burning, is as bright 

 as that of the sun and as white, so that the eye can 

 scarcely endure it ; and the effect is much increased 

 by the great quantity of silvery smoke caused by its 

 volatile oxide ; which reflects the fire, and thus widely 

 increases the sphere of illumination. For signal lights 

 it far exceeds any other substance ; a case of an inch 

 in diameter producing a flame that has been seen at 

 seventy miles, and would probably be visible at one 

 hundred. As a military light for discovering the ope- 

 rations of besiegers in their trenches, or for other ob- 

 jects of nocturnal discovery, it has no rival. It is also 

 very applicable for ornamental works, where it serves 

 to vary the colours and effects of light and of sparkling 

 fires. It is used in the shape of filings, and has the 

 advantage of being much more durable than iron when 

 made up. 



COPPER. The effect of copper is to give a greenish Copper, 

 light ; but it is not easy to produce, as the colour is 

 destroyed by too active an inflammation. The nitrate 

 and other salts of this metal will answer this purpose : 

 but they are expensive, and have not been introduced 

 by the firework makers. In the form of filings, it is 

 apt to fail, and the common practice is to use verdigris. 

 Brass filings are recommended, in some books, to pro- 

 duce red sparks ; but they are burnt in the explosion, 

 so as to produce only light and smoke ; partaking in 

 some degree of the effects of zinc. We may add, that 

 some other modifications of colour may be produced by 

 some others of the metals ; but they are expensive, nor 

 are the effects such as to be worth purchasing at a great 

 price. 



NITRATE OF STHONTIAN. The effect of this salt, Nitrate of 

 lately introduced into ornamental pyrotechny, is to pro- 8tr o nt| a n - 

 duce a fine crimson light ; nor is it too expensive, con- 

 sidering that it gives a colour so beautiful, and hitherto 

 unknown in this art. 



ALCOHOL. Spirit of wine is recommended for many Aicohoi. 

 compositions, on the futile notion of adding to their in- 

 flammability. As it necessarily evaporates, it can pro- 

 duce no such effect. It is also recommended for tem- 

 pering gunpowder for quick-match, as it does not per- 

 mit the nitre to crystallize and separate from the other 

 ingredients. This object may however be attained well 

 enough with water, so that it may be considered as an 

 unnecessary expence. Vinegar has also been recom- 

 mended for the same purposes ; but it is of very little 

 use in this point of view, and may also be dispensed 

 with. 



As it is of use to know what to avoid as well as to 

 adopt from the various books, which no one is inclined 



