PYROTECHNY. 



231 



rizntion, to a torrent of sparks, producing one of the 

 ornamental effects which are desired in fireworks. It 

 is plain, therefore, that the ingredients of gunpowder, 

 which form the basis of all firework*, are moderated in 

 violence so^as to answer th" desired end, of a control- 

 l.i!)le iorce l>y three methods : impeded proportions, 

 imperfect pulverization, or mixture, and ha;d driving. 

 Tims ai'v OIK- of these can, in some nu.iMire, he made 

 to compensate the want of the other two, and, conse- 

 quently, the vuue effects are to be produced by compo- 

 sitions of different proportions, or different ones by 

 compositions of the same nature. As ornament in 

 the nppear;mce of the fire is, in mo^t of these cases, no 

 less important than force, so the fundamental composi- 

 tion is modified for that end by various additions. 

 These we shall consider now, in describing the compo- 

 sitions of which the sole purpose is ornament, or in 

 which force is, at least, only a secondary, consideration. 

 There can be but two modes of ornamental fire, 

 namely, flame and sparks, however these may be vari- 

 ed and combined, whether as to colour, or quality, or 

 quantity, or mixture, or alternation, or, according to 

 their mechanical disposition in various kinds of work. 

 A separate management of the composition is required 

 for each of these. 



In compositions which are merely to flaino, slowness 

 of burning is necessary, and all sparks are excluded, 

 as purity of, colour, steadiness, arid duration, are. the 

 principal objects. Hence the basis of all these compo- 

 sitions must exclude charcoal as far as it is possible to 

 do without it, and the mixtures must also be as minute 

 and intimate as can be effected. Thus, wherever char- 

 coal is necessary, it is introduced in the form of mealed 

 powder, as it is there so fine as to yield no sparks, 

 while the requisite degree of feebleness or dilution is 

 obtained by diminishing the dose of nitre. Such is 

 the general basis of all compositions merely luminous, 

 whether in the shape of cases or stars ; and to it the 

 several ingredients intended to modify the colours of 

 the flame are added. All of these must also be most 

 finely powdered and intimately mixed, as it is only in 

 this manner that steadiness and clearness of flame. can 

 be produced. 



In compositions that are intended to sparkle, the or- 

 dinary mixture used for recoil forms the basis. Even 

 this may be rendered sufficiently brilliant by increasing 

 the charcoal, and using it in the state of a coarse pow- 

 der ; but it is also modified by the addition of other 

 sparkling substances, and principally of iron. As this 

 ingredient is extremely brilliant in its effect, it may also 

 be united to the simpler bases intended for flaming 

 compositions ; by which means its peculiar effects are 

 obtained in a state of purity. *It is so easy to under- 

 stand how these different kinds of composition may be 

 united or alternated, that it is almost superfluous to 

 mention it. Yet we may give one instance as an illus- 

 tration, by saying, that if iron be mixed, with the anti- 

 monial composition for a blue flame, the result will be 

 a firework discharging a blue flame, accompanied .by 

 brilliant white sparks. 



Of I he ddncral Mechanical Arrangement of Firetvorkf. 



Ofthege- THE mere fires of works in Pyrotechuy being thus 

 nerri me- limited in point of variety, it is chiefly by .their meeha- 

 chanical ni C al amusements and combinations that all their 

 range- S pl en di t i effects are produced. In some cases these 

 fireworks, arrangements are simple and inherent in the very na- 

 ture of the firework ; in others they are complicated in 

 various modes, so that there is scarcely any end to the 



varietic* which an ingenious artist can produce. A it 

 would be impossible within the limits of our article, to 

 describe even a small part of the arrangements of which 

 they are susceptible, we shall here give a sketch 

 general principles by which they are guided, so that 

 an artist of any resource will be able to produce, new 

 edicts without difficulty. Hereafter, the few varieties 

 which we shall select for consideration will serve for 

 examples of what may be done in this department of 

 the art; and on which, after such general remarks and 

 examples, it would be as little necessary to enlarge M it 

 would be to us impossible. 



The iMjJiitg distinction among fireworks is between 

 those winch are characterised by rest, and those to which 

 motion is essential. In the former, the effect depends sole- 

 ly on the quantity,the shape, and the colours of the fire, 

 if they are simple, and on the various ways in which 

 that is directed and combined in compound and com- 

 plicated works. Gerbes, which throw out a sparkling 

 fire, offer a good example of the simpler kinds, which 

 are indeed rarely used in this manner, without being 

 at least relieved by others, if not united and intermixed 

 with them. It is evident, however, that innumerable 

 varieties may be produced, merely by the combination 

 and disposition of the simplest fireworks. Thus, for 

 example, a bright star may bs made by five or six 

 small flaming lights, or speckies> radiating from a cen- 

 tre. In greater number, many such stars may be dis- 

 posed in various forms, either alone, or in combination 

 with other bodies. When in still greater numbers, such 

 illumination lights may be arranged in lines, or crosses, 

 or circles, or triangles, or in any other figures, and 

 those also may be intermixed in various ways. Be- 

 coming more compounded still, they may serve to de- 

 fine the architectural lines of a pyrotechnic building; 

 the other ornaments of which may exhibit all the vari- 

 eties of fire of wJiich the art is susceptible. Lastly, 

 that we may not dwell unnecessarily on this subject, 

 they may be disposed in the form of letters, so as to 

 express the names of individuals, or any "sentence con- 

 nected with the particular object of the firework which 

 is displayed. . 



The length and form of the torrent of fire in all the 

 sparkling compositions, render the possible combina- 

 tions of these still more numerous and various. Effects 

 may be produced by this intersection in this case, which 

 could not in the former ; as there also may by the 

 mere quantity of the fire. To put a few of the most 

 obvious instances: If a number of these are disposed 

 in a circle, they may form a blazing star or sun ; and 

 by again combining two such circles, the one of which 

 is of larger dimensions than the other on the same cen- 

 tre, an effect still more splendid may be obtained. 

 Three such fires properly dispersed may be made to re- 

 present a plume of feathers ; four may be caused to 

 produce a cross of fire. Such fires may also radiate 

 inwards as well as outwards, or they may lv disposed 

 so as to produce a pyramid, or a cascade ; or they may 

 cross or intersect each other from the angles of tri- 

 angles, or squares, or hexngqns, or any other geome- 

 trical figures ; ami in these ways the fires may be 

 directed outwards or inwards, or in both modes at 

 once. Different sizes may also be combined together 

 in various figures; but it would be endless to describe 

 all these possibilities, which may be safely trusted in 

 general to the taste and resources of the art is'.. We 

 subjoin a few figures in the plates by which a gene- 

 ral notion of their construction and effects may be 

 formed. 



