266 



PYROTECHNY. 



Of moveable Illuminations. 



Of move- 

 able illu- 

 minations. 



PLATE 

 CCCCLXXIII 

 Figs. 29, 

 30. 



Figs. 31, 

 32. 



Fig. 33. 



Fig. 3*. 



These also admit of great variety ; but we must for 

 the same reasons be satisfied with describing a few. 

 In general, it is a good rule that whatever motions 

 they are to receive should be given by means of wheels ; 

 but, as we formerly remarked in our observations on 

 machinery, this is sometimes not possible, owing to 

 their great weight and complication. Proper machi- 

 nery must then be adopted; yet there should always 

 be wheels attached, that the firework may at least have 

 the credit, in the spectator's eyes, of being able to pro- 

 duce its own motions. 



One of the most common and pleasing of these is a 

 spiral cone. The frame for this is attached to a hori- 

 zontal wheel revolving freely on its centre, and is pro- 

 vided with a spiral line, to which the lights are fixed 

 at a short distance. It may be of any dimension 

 which the artist chooses ; but a height of four feet, 

 with an angle of about thirty degrees for the cone, 

 forms a very convenient figure. The horizontal wheel 

 below is driven by horizontal brilliant fires, or by 

 oblique ones, in any of the modes formerly mentioned 

 when treating of horizontal wheels. Sometimes the 

 cone is terminated by a star or by a single gerbe. The 

 figure of an inverted cone is not pleasing, nor is that 

 of a double one ; but both may be used in large dis- 

 plays where variety is required. 



A cylinder may also be constructed in a similar man- 

 ner, and this may be very agreeably varied, by attach- 

 ing a horizontal wheel both above and below, by which 

 means also some additional revolving force is gained. 

 Cylinders revolving in this manner, may form a very 

 beautiful firework alone, if on the upper part there is 

 fixed a fountain of fire, so as to spread over on all sides. 



In all these figures, which have lights spirally dis- 

 posed, and which revolve at the same time, the effect 

 produced is that of a screw in motion, and hence they 

 are applicable to architecture, or in other combinations, 

 in a variety of ways. They may also be made to re- 

 volve horizontally ; and for this purpose two wheels 

 must be attached to the ends of a cylinder. Thus, 

 however, the particular effect of the wheel is lost to 

 the spectators, otherwise than as they will represent a 

 stream of fire at each end directed towards them. Such 

 a firework may however be rendered beautiful, by add- 

 ing to it some fixed cases that may throw their fires 

 upwards, so as to intersect above in the manner of a 

 Gothic arch. 



Erect cylinders may also be rendered entertaining, 

 by causing two, placed near each other, to revolve in 

 opposite directions ; and cones may also be treated in 

 the same manner. 



Lights placed on a spiral within a circle also produce 

 a pleasing effect, as the spiral appears to be unwinding 

 as the circle revolves. Such a figure may be inclosed 

 within a wheel of fire, or else the wheel may form the 

 centre of the spiral. Two spirals placed one before the 

 other, with their tendencies in opposite directions, and 

 turned in contrary ways, also produce a very striking 

 kind of firework ; but they require to be accompanied 

 by something else, as their appearance is otherwise 

 naked. They may form appropriate centres for a piece 

 of architecture, or they may be accompanied by cones 

 or spiral columns. 



The last method which we shall describe, is that of 

 placing lights round a globe; and this may be used at 

 rest or in motion, while the motion may also be either 



horizontal or vertical. This is a very handsome ar- Pyrotech- 

 rangement, and forms a very appropriate ornament for "7- 

 the heads of cones, or pyramids, or columns, or for s "*"Y""~ 

 particular parts on the outline of a piece of architec- 

 ture. The lights may be disposed on the globe in me- 

 ridians, or in lines parallel to the equator, or else in 

 spirals. This latter method is chiefly applicable where 

 they are to turn in a vertical manner. Or lastly, if the 

 globe is of large size, the lights may be disposed all 

 over it at equal distances, so as, if near, to represent a 

 very solid globe of spotted fire. In this case they 

 should not revolve. 



The frame work for globes must be disposed accord- 

 ing to the different ways in which it is intended to 

 place the lights ; and when they are to revolve, a pro- 

 per axis must also be provided. They may also be 

 caused to revolve by means of wheels, in which case 

 they produce complicated appearances, and it is also 

 an improvement on them for particular purposes, that 

 they should terminate by a gerbe. If very large, they 

 may contain one large light in the centre. 



Of the Dodecahedron. 



We feel it a duty to mention this firework because Or the do- 

 it is found in all the books, but chiefly for the purpose decahe- 

 of cautioning the artist against it. It is what its name dron - 

 expresses, a dodecahedron, carrying a wheel upon each 

 face. The effect of this is as confused and bad as the 

 contrivance is in itself expensive. Many other similar- 

 ly confused arrangements are to be found in all these 

 books, which, like the compositions which we have 

 elsewhere condemned, seem to have been put down 

 by mere guess, without even the trouble of considering 

 what the effect would be on burning. We shall not, 

 however, crowd our pages with any more of this use- 

 less matter. Our only object is to caution the artist 

 against making up any firework from these printed di- 

 rections, till he has well considered what its effect will 

 be when lighted ; and for this purpose, he will be 

 much assisted by making a detailed drawing of its fires 

 on paper, in the manner we formerly suggested. He 

 must in all his contrivances, whether borrowed or ori- 

 ginal, carefully consider not only the general pictu- 

 resque forms and other circumstances formerly de- 

 scribed, but how the fires are likely to interfere with 

 each other ; as, for want of such attention, he may gain 

 nothing for his trouble but a scene of confusion. And 

 as all cases throw their fires to a considerable distance, 

 with the exception of lights, he must especially take 

 that into consideration, and not imagine that he has ob- 

 tained any particular figure merely because the cases 

 are disposed in a pleasing manner, or in some determi- 

 nate form. 



There is another great object to be considered in all 

 these contrivances, and that is economy. This dode- 

 cahedron is a very good example of the neglect of this 

 essential quality; as in destroying eleven wheels at 

 one time, scarcely one half of them would be visible. 

 The best effects are often produced by the least fires, 

 provided they be tastefully disposed, and the artist 

 cannot do better than keep in his mind the singular 

 economy of the Chinese in all their fireworks, as they 

 often produce better effects than ourselves with a 

 tenth part of the fire. To keep the fires at a sufficient 

 distance from each other, that their figures may not 

 interfere, is the first requisite for this object; as far 

 greater extent, with greater beauty at the same time, 

 is thus produced. Even in many of the fireworks 



