PYROTECHNY. 



render them mftre llrikiiig, they are made in the form of 

 different animals, fuch as ferpents, dragons, Sec. 



To give a rocket a kind of rotatory motion around the 

 rope along vvhicli it advances, it will be fufficient to tie to 

 it another rocket, placed in a tranfverfal direftion. But 

 the aperture of the latter, inllead of being at the bottom, 

 ought to be in the fide, near one of the ends. If both 

 rockets be fired at the fame time, the latter will make the 

 other revolve around the rope, while it advances along il. 



Roclets which burn in the Water. — In thefe there mud be a 

 confiderable variation in the conftruftion of the mould, and 

 alfo in the materials of which they are compoied. The 

 mould may be eight or nine inches ii? length, and an inch in 

 diameter : the former, on which the cartridge is rolled up, 

 may be nine lines in thicknefs. The compofition fiiould 

 confiil of three materials mixed together, viz. three ounces 

 of mealed powder, one pound of faltpetre, and eight ounces 

 of fulpliur. If the rocket is to appear on the water with a 

 beautiful tail, the cjmpofition mull confift of eight ounces 

 of gunpowder, one poiijid of faltpetre, eight ounces of 

 pounded and finely fifted fulphur, and two ounces of char- 

 coal. When the compofition has been prepared according 

 to thefe proportions, and the rocket has been filled in the 

 manner above defcribed, apply a laucidon to the end of it, 

 and having covered the rocket with wax, pitch, &c. attach 

 to it a fmall rod of white willow, about two feet \\\ length, 

 that the rocket may conveniently float. If it be required 

 that thefe rockets fiiould plunge down, and again rife up, 

 a certain quantity of mealed gunpowder, without any mix- 

 ture, muft be introduced into them, at certain diftances. 



A rocket which is fired in the water, and, after burning 

 there half the time of its duration, mounts into the air with 

 great velocity, may be thus conftrufted. Take a Jlfnig 

 rocket, furnilhed with a rod, and by means of a little glue 

 attach it to a water-rocket, but only at the middle, A, {fg. 6.) 

 in fuch a manner that the latter (hall have its neck upper- 

 mod, and the other its neck downward. Adjud to their 

 extremity, B, a fmall tube, to communicate the fire from the 

 one to the other, and cover both with a coating of pitch, 

 wax, &c. that they may not be damaged by the water. 

 Then attach to the flying rocket, after it has been thus ce- 

 mented to the aquatic one, a rod, as D, and from F fufpend 

 a piece of packthread, to fupport a mulket bullet E, made 

 fad to the rod by means of a needle or piece of iron wire. 

 When thefe arrangements have been made, fet fire to the 

 part C after the rocket is in the water ; and when the com- 

 pofition is confumed to B, the fire will be communicated 

 through the fmall tube to the other rocket ; the latter will 

 then rife and leave the other, which will not be able to 

 follow it, on account of the weight adhering to it. 



Globes and Fire-BaUs are made in different forms, vi%. 

 fpherical, fpheroidal, or cylindrical. The fpherical are 

 made in the following manner. Condrutt a hollow wooden 

 globe of any fize at pleafure, and very round both within 

 and without, fo that its thicknefs, A C or B D, (jig. 7.) may 

 be about the ninth part of its diameter A B, and having an 

 aperture, L M or O N, equal to the thicknefs A C or B D, 

 that is, to the ninth part of the diameter A B. It is through 

 this aperture that fire is communicated to the gk)be, ivhen 

 it has been filled with the pi-oper compofition, through the 

 lower aperture IK. A petard of metal, loaded with good 

 grained powder, is to be introduced alfo through the lower 

 aperture, and to be placed horizontally. The aperture I K, 

 which is nearly equal to the thicknefs, E F or G H, of the 

 cyhnder E F G H, is to be clofed by means of a wooden 

 tompion dipped in warm pitch ; and melt over it fuch a 

 quantity of lead that its weight may caufe the globe to fink 



Vol. XXIX. 



in water, till nothing remain above it but the part G H ; 

 which will be the cafe if tlic vreight of the lead, with that 

 of the globe and the compofition, be equal to the weight 

 of an equal volume of water. If the globe be then placed 

 in the water, the lead, by its gravity, will keep the aperture, 

 I K, diredly dov/nwards, and the cylinder, E. F G H, in a 

 perpendicular diredtiun, to wiiicii fire mull have been pre- 

 vioufly applied. The compofition witii wiiich tiic globe 

 mud be filled, is as follows : to a pound of corned powder, 

 add thirty-two pounds of faltpetre, eight pounds of fulphur, 

 one ounce of fcraped ivory, and eigiit pounds of faw- 

 dud previoufly boiled in a folution of faltpetre, and dried in 

 the open air. 



Globes "jjhich leap or roll on the Ground. - Having con- 

 drufted a wooden globe A, (Jig. 8.) with a cylinder C, iimilar 

 to the one jud defcribed, and having loaded it with the 

 fame compofition, introduce into it fi)iir or even more 

 petards, loaded witii good corned powder to their orifices, 

 as is (hewn at A B, which mud be well (lopped with paper 

 or tow. If a globe, prepared in this manner, be fired by 

 means of a match at C, it will leap about as it burns, on a 

 fmooth horizontal plane, according as the petards ai-e fet on 

 fire. The petards may be affixed to the exterior furface of 

 the globe, as is feen in the figure, which they will caufe to 

 roll and leap as they catch fire. 



Aerial Globes, called Bombs. — Thefe glubes are called 

 aerials, becaufe they are thrown into the air from a mortar. 

 Though they are of wood, and have a fuitable thicknefs, 

 yet they are liable to biird unlcfs the charge be nicely pro- 

 portioned to their itrength. The ufual quantity is an ounce 

 of powder for a globe of four pounds weight ; two ounces 

 for one of eight, and fo on. As the chamber of tlie mortar 

 may be too large to contain the exadt quantity of powder 

 fufficient for the fire-ball, which ought to be placed imme- 

 diately above the powder, in order that it may be expelled 

 and fet on fire at the fame time, another mortar may be con- 

 dructed of wood, or of pade-board with a wooden bottom, 

 which may be put into tlie large iron mortar, to be loaded 

 with a quantity of powder proportioned to the weight of 

 the globe. This fmall mortar mud be of light wood, or of 

 paper palled together, and rolled up in the form of a cylin- 

 der, but the bottom muft be of wood. The chamber for 

 the powder muft be pierced obliquely, fo that the aperture 

 may correfpond to the aperture of the metal mortar, then 

 the fire applied to the latter may be communicated to the 

 powder which is at the bottom of the chamber, immediately 

 below the globe. 



The globe muft be filled with feveral pieces of reed or 

 cane, or common reed equal in length to the interior height 

 of the globe, and charged with a (low compofition, made 

 of three ounces of mealed gunpowder, an ounce of fulphur 

 moidened with a fmall quantity of petroleum oil, and two 

 ounces of charcoal ; and ui order that thefe reeds or canes 

 may catch fire the fooner, and with more facility, they muft 

 be charged at the lower ends, which reft on the bottom of 

 the globe, with pulverized gunpowder moidened with pe- 

 troleum oil or brandy, and then drie-^. The bottom ot the 

 globe ought to be covered with gunpowder, partly mealed 

 and partly corned, which, when fet on fire, will communi- 

 cate the lire to the lower p:ut of the reed. Inftead of reeds, 

 the globe may be charged with running rockets, or paper 

 petards, and a quantity of fiery ftars or fparks mixed with 

 mealed powder placed above thele petards, which mull be 

 choaked at unequal heights, that they may produce their 

 efFeftsat different times. 



Jets of Fire are a fort of fixed rockets, the effefl of which 

 is to tlurow up into the air jets of fire fimilar to jets of water. 



N They 



