PYROTECHNY. 



"fhey ferve alfo to reprefent cafcades, for if a feries of fuch 

 rockets be placed horizontally on the fame line, it may be 

 eafily feen that the fire wliich they emit will refemble a fheet 

 of water. When arranged in a circular form, like the 

 radii of a circle, they form what is called a fixed fun. To 

 form jets of this kind, the cartridge for brilliant fires muft, in 

 thicknefs, be equal to a fourth part of the diameter, and 

 for Chinefe fire only a iJxth part. The cartridge is loaded 

 on a nipple, having a point equal in length to the fame dia- 

 meter, and in thicknefs to a fourth part of it ; but as it 

 generally happens that the mouth of the jet becomes larger 

 than is neceflary for the effeft of the fire, the cartridge muft 

 be filled equal to a fourth part of the diameter with clay, 

 which muil be rammed down. This will make the jet afcend 

 much higher. When the charge is completed with the 

 proper compofition, the cartridge mull be clofed with a 

 tompion of wood, above which it muft be choaked. Jets 

 intended for reprefenting (heets of fire ought not to be 

 choaked. They muft be placed in a horizontal pofition, or 

 inclined a little downwards. The following are the prin- 

 cipal compofitions for jets of fire. 



1. For Jets of half an Inch or Itfs in Diameter. — Chinefe 

 Jire : Saltpetre and mealed powder lib. each ; fulphur S 



ounces; charcoal 2 ounces. — White fire : Saltpetre ilb. ; 

 mealed powder 8 ounces ; fulphur 3 ounces ; charcoal 2 

 ounces ; iron-fand of the firft order 8 ounces. 



2. For Jets of an Inch or lefs in Diameter. — Brilliant fire : 

 Mealed powder lib., iron-lilings 5 ounces. — White fire : 

 Saltpetre and mealed powder lib. each ; fulphur 8 ounces ; 

 charcoal 2 ounces. — Chinefe fire : Saltpetre 16 ounces ; ful- 

 phur 5 ounces ; charcoal 5 ounces ; iron-fand of the third 

 order 1 2 ounces. 



3. For Jets 0/" 15 or 18 Lines in Diameter. — Chinefe fire ; 

 Saltpetre 16 L:u:;ces ; fulphur 7 ounces ; charcoal 5 ounces ; 

 of the feveral different kinds of iron-fand mixed 12 ounces. 



Fires of different Colours. — For white fire the gunpowder 

 muft be mixed with iron or rather fteel-filings : for red fire, 

 iron-fand of the firft order muft be employed in the lame 

 way. Camphor mixed with the ufual compofition is faid to 

 make the flame appear of a pale white colour. Raipings of 

 ivory give a clear flame of a Clver colour. 



Pafle for reprefenting Animals, \^c. in Fire. — Take fulphur 

 reduced to a very fine powder, and having formed it into 

 a pafte with ftarch, cover it with the figure of the thing to 

 be reprefented, having firft coated it with clay to prevent it 

 from being burnt. After the figure is covered with the 

 pafte, it muft be fprinkled, while moift, with gunpowder ; 

 and when the whole is perfectly dry, arrange about it feveral 

 fmall matches, that the fire may be fpeedily communicated 

 to it on all fides. In this way all forts of garlands, feftoons, 

 and other ornaments, may be imitated by fire of different 

 colours. 



Suns,flxed and moveable. — For fixed funs, let a round piece 

 of wood be cut, into the circumference of which are to be 

 fcrewed twelve or fifteen pieces in the form of radii, to 

 which are to be attached jets of fire, of the compofition 

 defcribed above ; fo that they may appear as radii tending 

 to the fame centre, the mouth of the jet being towards the 

 circumference. Apply a match in fuch a manner that the 

 fire communicated at the centre, may be conveyed at the 

 fame time to the mouth of each of the jets, by which 

 means, each throwing out its fire, there will be produced the 

 appearance of a radiating fun, that is, fuppofing the w'i;el 

 is placed in a pofition perpendicular to the horizon. The 

 rockets or jets may be fo arranged ai to crofs each other in 

 an angular manner, in which cafe, inftcad of a fun, you will 

 have a ftar, or a crofs. Some of thefe funs are made alfo 



with feveral rows of jett, which are called glories. For re- 

 volving funs, provide a wooden wheel, and attach to the cir. 

 cumference fire -jets placed in the diredlion of the circum- 

 ference : they muft not be choaked at the bottom, and ought 

 to be arranged in fuch a manner, that the mouth of the one 

 fliall be near the bottom of the other, fo that when the fire 

 of the one is ended, it may immediately proceed to another. 

 When the fire is apphed to one of thefe jets, the recoil of 

 the rocket will make the wheel turn round, unlefs it he too 

 large and ponderous. For this reafon, when thefe iuns are 

 of a confiderable fize, that is, when they confift of perhaps 

 twenty rockets, fire muft be communicated at the fame time to 

 the firft, the fixth, eleventh, and fixteenth, from which it will 

 proceed to the fecond, the feventh, the twelfth, the feven- 

 teenth, and fo on. Thefe four rockets will make the wheel 

 turn round with great rapidity. If two fimilar funs be 

 placed one behind the other, and are made to turn in a con- 

 trary direftion, they will produce a fine effedt of crofs- 

 fire. 



Making, loading, and firing Pols des Brins. — Thefe are 

 made of palle-board, and muft be rolled pretty tlnck ; ufually 

 made three or four inches in diameter, and four diameters 

 long, and pinched with a neck at one end, like common cafes. 

 A number of thefe are placed on a plank thus : having 

 fixed on a plank two rows of wooden pegs, cut in the bot- 

 tom of the plank a groove the whole length under each row 

 of pegs ; then, through the centre of each peg, bore a 

 hole down to the groove at bottom, and on every peg fix and 

 glue a pot, whofe mouth muft fit tight on the peg : through 

 all the holes run a quick-match, one end of which muft go 

 into the j;ot, and the other into the groove, which muft 

 have a match laid in it from end to end, and covered with 

 paper, fo that, when lighted at one end, it may difcharge 

 the whole almoft inftantaneoufly : in all the pots put about 

 one ounce of meal and corn powder ; then in fome put ftars, 

 and others rains, fnakes, ferpents, crackers, &c. : when they 

 are all loaded, pafte paper over their mouths. Two or 

 three hundred of thefe pots being fired together, make a 

 ver)- pretty (how, by aff^ording fo great a variety of fires. 

 Fig. 9. is a range of pots des brins, with the leader A, by 

 which they are fired. 



Caduceus Rockets, in rifing, form two fpiral lines, or dou- 

 ble worm, by reafon of their being placed obliquely, one 

 oppofite the other ; and their couRterpoife is in their centre, 

 which caufes them to rife in a vertical direftion. Rockets 

 for this purpofe muft have their ends choaked clofe, without 

 either head or bounce, for a weight at top would be a great 

 obftruftion to their mounting ; though they have been known 

 fometimes to be bounced, but then they did not rife fo high 

 as thofe that were not ; nor do any caduceus rockets afcend 

 fo high as fingle, becaufe of their ferpentine motion, and 

 hkev.nfe the refiftance of air, which is much greater than two 

 rockets of the fame fize would meet with, if fired fingly. 



By fg. 10. we fee the method of fixing thefe rockets : 

 the fticks for this purpofe muft have all their fides equal, 

 which fides fliould be equal to the breadth of a ftick proper 

 for a (Icy-rocket of the fame weight as thofe we intend to 

 ufe, and to taper downwards as ufual, long enough to ba- 

 lance them, one length of a rocket, from the crofs ftick, 

 which muft be placed from the large ftick, fix diameters of 

 one of the rockets, and its length feven diameters ; fo that 

 each rocket, when tied on, may form with the large ftick an 

 angle of fixty degrees. In tying on the rockets, place their 

 heads on the oppofite fides of the crofs ftick, and their ends 

 on the oppofite fides of the long ftick ; then carry a leader 

 from the mouth of one into that of the other. When thefe 

 rockets are to be fired, fufpend them between two hooks or 



nails. 



