P V R O T E C H N V. 



K29 



to distrust from t!u manner in which the ef- 



.1 of, \u->>hall continue 

 m i)t' tlif-i- in it u -rs, merely for the pur- 

 'ndemning tlieai. U'e shall, in this manner, 

 :iti>ts from mueh labour, cxpcnre, antl di-;.p- 

 pointmt-nt. With respect to many oi' them, the uses 

 iutely imaginary ; and of others, from their 

 palpable absurdity, we c-an only think that they must 

 have been recommended lor the sole purpose of blind- 

 ! misleading tlio-e n ho trust to these receipts. We 

 '. have occasion again hcrealler, in examining the 

 directions given for making many compositions, to see 

 that they are either impracticable or absurd, or incapa- 

 ble of answering the ends proposed. We can only 

 therefore conclude, either that the authors of these 

 books were entirely ignorant of their subjects, or else 

 that their designs were to maintain secrets which they 

 considered valuable, while they professed to disclose 

 them. To clear out all this rubbish, we consider even 

 more necessary than to describe how the required ob- 

 jects may be attained ; nor without such an explana- 

 tion and examination, indeed, would our readers be 

 able to comprehend why we had varied so much from 

 aur predecessors, and to whom credit ought to be given. 

 The assignment of reasons, and the sort of criticism we 

 shaH here use, will enable the readers of this article to 

 judge what is right on this subject, from principles. 

 The work of Captain Jones, so called, the chief reposi- 

 tory of these impracticable and false receipts, will be 

 among the principal ones to be thus examined, because 

 it is the standard book. The artificers in fireworks, 

 however, as well as ourselves, know pretty well where 

 its faults lie, though still misled by it in many particu- 

 lars. 



BKNZOIN. This is recommended as an ingredient 

 in fireworks for the purpose of producing a perfume. 

 It is converted into " flour," as the receipt says, by 

 putting it into an earthen pot, which is to be covered 

 with paper, and then exposed to the fire. This flour 

 is to be returned into the pot, and treated in the same 

 way till it is perfectly white and fine. It is evident 

 that this is a bad method of procuring benzoic acid, 

 which may be obtained much cheaper from the drug- 

 gists, were it of any use. But in the burning of a fire- 

 work this substance is not evaporated but destroyed, 

 and consequently it can yield no perfume. An imagi- 

 nary perfumed oil of Benzoin is also recommended for 

 wet compositions for the same end, when there is no 

 such thing known. 



OIL, OF SPIKE. This is an expensive essential oil, 

 all the purposes of which may be served by the oil of 

 turpentine ; but in fact none of these essential oils are 

 required for ornamental fireworks;. To say the least 

 of them, they are useless. 



SULPHUR VIVUM. This is the sulphuret of lime 

 which remains alter the ordinary purifications of sul- 

 phur by melting. It will scarcely burn at all alone, 

 and very imperfectly with nitre ; whence it is easy to 

 conjecture what results are to be expected from the 

 numerous compositions into which it enters. 



ISINGLASS This is used or recommended to make 

 up the composition for stars into balls ; but it is infe- 

 rior for these purposes to gum, which is therefore here 

 recommended. If too much gum lx? used, the ready 

 < ension of the stars is impeded. If flour paste be 

 used, the quantity of carbonaceous matter is so great, 

 that they sometimes will not burn at all unless the 

 Lapis cla- quantity of charcoal in them is reduced, 

 minaris. LAPIS CALAMiNARts. This is recommended as pro- 



Benzoin. 



Oil of 

 spike. 



Sulphur 

 vivum. 



Isinglass. 



ducing what is called a " dead fire." On the same 

 principle as clay, it would not only deaden but ex- "7- 



tinguish any fire, and is, if not injurious, a nugatory *""" '""" 

 ingredient. 



S\\v IJUBT. There is no advantage in saw dust Haw duct. 

 which is not to be obtained' by charcoal. In the very 

 large cases it may burn in sparks, but not better than 

 that substance does ; and in the small ones it is much 

 more likely to extinguish than to maintain the fire. 



AMBKR. This is one of the useless substances re- Amber, 

 commended in all the books. It is only calculated to 

 make a bad flame in* large cases, and smoke in small 

 ones. It may be safely rescinded from the catalogue 

 of necessaries altogether. 



CLAY. This is a necessary ingredient for the pur- c'Jay. 

 pose of stopping up various fireworks. It is indispen- 

 sable in tourbillons and simple wheels, or in all cases of 

 fire that are to burn at the sides instead of the ends. 

 In the cases which are choked, for the purpose of burn- 

 ing the iron more effectually, it is also useful, as it 

 may be rammed down in the vent, and being after- 

 wards perforated, it serves to protect the paper about 

 the choke from burning, and thus preserves the aper- 

 ture of the same size. In the military iron rockets it 

 is indispensible, to prevent the plate which contains 

 the vent from being destroyed by the torrent of fire ; 

 and it ought always to be used in the larger paper rock- 

 ets, for preserving the dimensions of the hole during 

 tho burning. Clay for these purposes ought always to 

 be freed from sand, to prevent all risk of accidents in 

 driving. This the artificer must do for himself, as it is 

 not to be procured thus pure. To effect this, it is in- 

 troduced into a cask with water, through which plug 

 holes may be made towards the middle and the top. 

 The water and clay being then stirred up, and suffered 

 to stand for a few seconds, the sand subsides to the 

 bottom. If then the muddy water be drawn off in 

 succession through the holes, the finer clays will be 

 suspended in two degrees of tenuity, should that be 

 thought necessary. After it has subsided, and the 

 water is drawn off, it is to be dried and powdered, and 

 thus reserved for use. 



FRANKINCENSE, MYRRH. After the remarks which Krankin- 

 we made on benzoin, it is almost fruitless to say any cent*. 

 thing about these gums, since they are equally useless. Myrrh. 

 It ought, however, to be known to all makers of fire- 

 works, that none of these substances yield a smell un- 

 less they smoke, and that at a low heat. Whenever 

 they burn, or when the heat is raised, all smell is de- 

 stroyed ; and there is no species of firework, unless 

 pastilles are included under this form, in which the 

 heat will not burn all these inflammable substance?. It 

 is much more amusingly absurd, to find oil of roses 

 and oil of bergamot recommended as ingredients in 

 fireworks. 



But we will not pursue this part of our subject fur- 

 ther, as our readers may, after these remarks, be ena. 

 bled to judge without much difficulty respecting the 

 value and uses of such fantastic ingredients. Yet, that 

 our criticisms may not appear unreasonable or unfound- 

 ed, we subjoin one of Captain Jones's receipts for the 

 composition of what he calls an " odoriferous water 

 balloon." 



" Take of saltpetre four ounces, sulphur one ounce 

 saw dust of juniper half an ounce, saw dust of cypress 

 an ounce, myrrh two drachms, dried rosemary a quar- 

 ter of an ounce, cortex elaterii half an ounce; all to 

 be moistened with oil of roses." On this we need only 

 remark that it will not burn, to say nothing of the saw 



