P Y R O T E C II X V. 



a 3.5 



PLATE 

 CCCCIXSII 

 Fig. 5. 



c ,o Lrye, that when ti: ihe case it will 



m:i:er one-half of the interior diameter, so 

 is ivc] ui red for each size of 

 it be. provided with a handle, and l>e 

 10 eoiMnirted as to enter entirely into tlie case, that 

 no i-ompoMtion may IK- lo*t, as every tiling in t! 

 curacy of the performance depends on these minute 

 attentions. In driving, it is necessary first to give a 

 i iille blows, that the composition may be con- 

 I before much force is used; as otherwise tlic 

 condensation of the air would blow it out ; and the 

 workman mu^t . care to turn the rr.mm.er, and 



it in the case before every blow, to prevent it 

 ring jammed by the materials mounting up br- 

 r.Men it ;.n(i the .-ides of the tube. The same num- 

 ber of blows, and with the same mallet and force, 

 must be given to cr.cli ladle-full of the composition ; 

 as these are essential to a correct performance. In 

 nailer, or in those which reach from two to four 

 ounces, sixteen strokes are sufficient ; a rocket of one 

 pound will require thirty ; of two pounds, forty; of 

 four, fifty; and of six, sixty. But beyond two pounds, 

 we must remark, the force of a man's arm is scarcely 

 available, and it becomes necessary, as in the military 

 iron rockets, hereafter mentioned, to adopt the pile 

 engine. We already remarked, that the rammers re- 

 quire to be changed as the composition advances. 



When the rocket is filled to the top of the spindle, 

 the quantity of a whole diameter in depth must then 

 l>e addetl, in the same manner, by means of the short 

 solid rammer, when the composition is completed. 

 Above this must be rammed one-third of a diameter 

 of clay, which being afterwards perforated by a small 

 gimlet, a communication is made between the rocket 

 and its head. 



The sky-rocket, thus far completed, must measure, 

 from the choke, five diameters and a quarter, and the 

 cases must then be cut to that length. The head is 

 then to be fixed on. Where it is judged essential to 

 have the highest flight, its diameter should not ex- 

 ceed that of the rocket, farther than the requisite 

 thickness of its case demands. But as in this way it 

 can contain but a small quantity of stars, or ornament 

 of any kind, it is usually made larger, and so as to ex- 

 ceed the exterior diameter of the case by a quarter of 

 an inch all round, for diameters of an inch. The height 

 is in this case near two inches, and in all other sizes 

 the same proportions are preserved. This case or head 

 is made slender, of two or three turns of paper at most, 

 as it is sufficiently strong if it will bear the ordinary 

 rough usage of packing and carrying ; and it is sur- 

 mounted by a paper cone of the same strength, which, 

 for the same dimensions, is an inch and three quarters 

 in length. If the head is simply larger than the case, 

 it may be glued on at once ; but if much larger, a ring 

 of turned beech wood is interposed, and the whole is 

 firmly glued together. 



But preparatory to this, it is necessary that the head 

 should receive its charge, whatever that may be. The 

 directions for making stars will be found elsewhere ; 

 but we may here say, that if these are made in the or- 

 dinary form of balls, or short cylinders, they do not 

 pack close. A better mode is to make the stars in a 

 cylinder of the same diameter as the rocket head, and 

 in the form of sectors, by which means they pack close- 

 ly in their place. This is easily done by means of an 

 appropriate copper mould, or else the cylinder may be 

 made, and then divided into compartments by a knife 

 before drying. The directions for making serpents, or 



raini, or by whatever name thec ornaments may be 

 called, are also given in their proper place*; and we 

 need scarcely add, that the length* of these mn 

 all caves, be determined by that of the head in which 

 they are to be enclosed. Before the rocket head it fix- 

 ed on, care must be taken that the priming hole into 

 the composition is free : as many ornaments of what- 

 ever nature as it will contain are then enclosed in tht 

 head, together with the requisite quantity of mealed 

 powder, when the operation of fixing it in may be 

 completed. A quantity of this, equal to one diameter, 

 or less, of the rocket, is amply sufficient for bursting 

 the head, and inflaming the ornaments." 



These ornaments are not very numerous, and we 

 may describe them in a few words. The *tars admit 

 of being made of two or three colours, as will be seen 

 when their compositions are mentioned ; but the dil- 

 ferences to the eye are so small at the distance where 

 they are seen, that it is scarcely necessary to use any 

 but the blue intimonial one. tor the serpents, in the 

 same way, all kinds of sparks have pretty much the 

 same effect at that great distance, so that the most or- 

 dinary charcoal composition answers as well as any 

 other. Where stars or serpents are to be used for 

 ground fireworks, these differences are worth attending 

 to, because they are visible. There is a species of ser- 

 pent, however, called scrolls, which may also be used, 

 and which are made on the same principle as the tour- 

 billon : they are described hereafter. Lastly, crackers 

 or maroons may be introduced into rocket heads, ei- 

 ther alone, or in company with other ornaments, and 

 the effect of these is amusing. They may be combined 

 with the serpent or not. If the former plan be adopt- 

 ed, half the serpent case is fitted with the proper com- 

 position, and it is then nearly choked and secured, 

 after which the remainder is filled with powder and 

 choked close. If crackers alone are used, they must 

 consist of similar cases filled entirely with powder ; 

 but they require a priming of cotton slow-match to 

 give them time, that they may not explode within the 

 head. The discretion of the artist will easily teach 

 him how to vary all these subsidiary matters. 



The last thing which remains is to close the mouth 

 of the rocket with a strong covering of paper, and to 

 fasten on the stick. This must be made of very straight 

 deal, and planed smooth. For the rocket, whose di- 

 mensions were given above, its length is to be eight 

 feet or more, but not less. At the upper extremity its 

 breadth should be about three quarters of an inch, and 

 at the lower one about a third. It may be wider than 

 it is thick above ; but the extremity must be square, 

 that the air may act alike on it in all directions. In 

 fixing it to the stick, it is better if it extends all the 

 way to the rocket head ; and it is to be fastened round 

 the case by two distinct windings of twine, which are 

 to be sunk in notches within it, that all unnecessary 

 resistance to the air, or chance of friction in going off 

 the support, may be avoided. The equilibrium should 

 be such, that, in this rocket, whose dimensions have 

 here been taken as a standard, the whole should be 

 poised on the finger at two inches from the mouth of 

 the rocket. This will serve as a general rule for 

 all. But as it is convenient, in the larger rockets, 

 to dispense with length of stick as far as possible., 

 on account of its expence and inconvenience, and, 

 as in the small ones, it is of little consequence how long 

 they are, provided the proper weight and equilibrium 

 are maintained, we shall subjoin a table of measure - 

 ment on this subject. We need only add, that, if on 



fyro-.ttk. 





