PYROTECHNY. 



ryrotcch- 

 V? 



it in its pl&ce, the upper empty part of the cylinder or 

 case is beat in o/er it. 



The cap or head of the rocket is a cylinder of plate 

 iron terminated l>y a cone. The cylinder tor the large 

 si/os is six iiiclu-s lung, will) two nHu-s more lor gores 

 on which the cone is fixed. The diameter of the cy- 

 linder is the same as that of the rocket, and the length 

 of the cone is equal to this double diameter, so as to be 

 HII acute one. At its extremity is a steel point, which 

 may be squared and notched backwards like a fish 

 hook, or a barbed spear. There are three holes in the 

 rylinder, and six in the cone; in some, as we formerly 

 mentioned, there are only three altogether. 



The head is sometimes charged with powder for 

 bursting, as we formerly remarked, in which case it 

 has no holes. Sometimes also it is filled with the or- 

 dinary e.uv.ise composition, as we formerly observed, 

 or also with the following, consisting of sulphur 24 

 parts, saltpetre 8, mealed powder 12, and corned pow- 

 der 4. Before filling it, the holes are to be covered 

 with a piece of cartridge paper glued on them. If it is 

 to be filled with a melted composition, a spindle is first 

 to be placed in the middle, for the purpose of leavings 

 hole, by which the inflammable matter may be lighted 

 from the last burning of the rocket. If all the holes are 

 to burn at once, a bore must be made from this main 

 spindle hole to each, which is easily done while the 

 composition is still soft. All these are to be filled with 

 proper priming and quick-match, so that a complete 

 communication may exist between the cap and the 

 rocket. 



The cap or head must now be fixed on the rocket 

 and driven down, so that the composition may come 

 close down on the clay or wadding, and that no va- 

 cuity may be left. This is done by means of a ham- 

 mer and a wooden block, with a hollow cone in it, 

 made to receive the conical part of the head. Four 

 holes must now be drilled through the cap cylinder 

 and that of the rocket, into the place where the wad- 

 ding lies. Four nails or wooden screws are then to 

 be put in, to fix the head firmly on. When this is 

 done, the whole head is to be covered with pitched 

 canvass, which is to be further secured by a proper 

 woulding of twine ; and the whole being then pitched, 

 the rocket is completed. 



The next part of the rocket requiring attention is 

 the stick. This is a piece of the straightest white deal, 

 free from knots, and of a quadrangular shape, so as 

 not to be flexible. It tapers slightly from the extre- 

 mity near the vent towards the opposite end, and is 

 hollowed out on one side above to receive the rocket. 

 The sticks are fastened on to the rockets by two 

 wouldings of strong twine, one placed an inch from 

 the vent, and the other four inches farther up. Both 

 of these are imbedded in a notch within the wood, 

 that it may meet with no impediment in starting from 

 the frame when it is fired. These sticks are balanced 

 as in the common signal rockets. There is further a 

 hole cut in the stick, between the ligatures, for receiv- 

 ing a pin placed on the frame. This is made in such 

 a manner that the rocket can hang on it when elevated ; 

 but it is so chiseled out downwards as to offer no im- 

 pediment to its quitting the frame when fired. Be- 

 sides this, the upper end of the stick is bevelled off, 

 down to the iron of the case, that it may meet with as 

 little resistance as possible from the air. 



The stick is not tied on till the rocket is about to be 

 used, nor are the rockets primed till then. This is 

 done by means of a quick match, which is fixed by a 

 nail upon the stick close to the vent. One end of this 



VOL. XVII. PART I. 



is inserted into the vent, and the other rum downwards Pjroucb. 

 on the stick, where it is to be lighted by the port fire. "7- 



It i* necessary to take great care that thi match be 

 not pushed up into the vent. If that should happen, 

 too much of the interior surface of the bore will take 

 fire while the rocket is on the frame, and the conse- 

 quence may be, that it is thrown out of its position by 

 the shock, so as to take a wrong direction, and be ren- 

 dered useless. 



If the rocket is to be kept after loading, the vent 

 must be stopped with tow. The cup may then be fill- 

 ed with powdered charcoal, and covered with parch- 

 ment or paper, which is to be firmly glued on, and 

 then secured with a string. If they are to be carried in 

 carts, or to be exposed to much service, and to the risk 

 of accidents, a cone of soft wood, covered with paper or 

 cloth, of the size of the spindle on which they were 

 driven, must be put into the bore. By this means the 

 composition is secured from being shaken so as to 

 crack ; an accident which leads to their bursting at 

 the moment of firing. After the bore is thus secured, 

 the cup is filled with tow, and the paper cover fasten- 

 ed on as before. Great care must be taken to with, 

 draw this plug before firing, or the rocket will fail. 

 Last of all, the whole rocket must be painted with a 

 double coat of paint, for the purpose of preserving it 

 from the wet. 



The frame used for firing these rockets is contrived 

 so as to be elevated at different angles, and may be 

 provided with a plummet and quadrant to determine 

 that by. The other details of this machine could not 

 be made intelligible without a drawing ; and that is 

 scarcely necessary, as it is not difficult to construct 

 them in many ways, and all answering the same pur- 

 pose. We shall now, therefore, subjoin a table of the 

 principal points in the three larger dimensions of these 

 rockets. The smaller ones are easily inferred. 



Mealed powder 

 Charcoal 



Mealed powder 



Nitre 



Charcoal 



Nitre 



Sulphur 



Charcoal 



Composition. 

 Small size. 



Larger do. 



Largest. 



8 Ib. ot. 



9 4 



8 

 1 

 4 



16 



4 

 9 



Oil of turpentine, from one ounce to half an ounce for each pound 

 of composition. 



Times of flight, from 3000 to 3500 yard*. 

 2 N 



