PYROTECHNY. 



22.5 



IVutecb. communicates with a crank handle outside, which the 

 ny. opi-rator manages. As the mixture begins to descend 

 the tube, the upper part of which lias its opening 

 regulated by a valve, which the *ame person can con- 

 tract or enlarge at pleasure, it falls on the vanes of this 

 little mill, which, being turned quickly round, pro- 

 duces an intimate and accurate union of all the parts, 

 and thus it is delivered complete at the lower end of 

 the tube. If it be judged necessary, it may pass 

 through two mills instead of one ; and, by means of a 

 band or string, both of these may be set in motion by 

 one hand. 



On a smaller scale, the mixture may be made in a 

 cylinder of wood, placed on its end, like an apotheca- 

 ry's mortar, and provided with a well-fitted cover. 

 Through a hole in this, there passes an axle and handle, 

 carrying vanes, placed vertically. The handle may be 

 turned between the hands, or, what is much better, by 

 means of a drill bow, somewhat in the manner prac- 

 tised with chocolate ; and, in this manner, a small 

 quantity of mixture can be completed in two or three 

 minutes. 



The third method is to introduce the ingredients in- 

 a sieve of moderate fineness, provided with a top 

 and bottom cover, so as to be completely enclosed. By 

 agitating this, the ingredients are carried through the 

 sieve into the receptacle below, and thus become accu- 

 rately mixed. 



If now it becomes necessary to mix fine and coarse, or 

 heavy and light ingredients together, a different practice 

 must be adopted. Supposing that antimony, or orpi- 

 ment, or any weighty substance in fine powder is requir- 

 ed, the mixture cannot be effectually performed in either 

 of these ways, to any extent ; as the unequal weights of 

 the materials will prevent the composition from being 

 uniform. The proper combustible ingredients, there- 

 fore, or the fundamental substances above mentioned, 

 must first be mixed in the requisite proportion, and 

 these additional matters may afterwards be introduced 

 and mixed up with them either by the hand or by a 

 comb with broad teeth. Coarser powdered charcoal, 

 intended to yield sparks, must be managed in a similar 

 manner. Greater care still is required, where metallic 

 filings, and particularly where large particles of iron 

 are to be used ; as these are apt to fall through the 

 lighter and finer dust, and thus to become unequally 

 disposed. They should, therefore, first be sifted as 

 equally as possible over the surface of the general or 

 fundamental mixture; after which, with a little care, 

 they may easily be diffused throughout in a regular 

 manner. Owing to their brilliancy and distinctness, 

 the eye is a good judge of the correctness of such mix- 

 tures as this. 



Of the Moulds, Rammers, and other Utensils required in 

 making Fireworks. 



Many of these utensils require to be made with such 

 accuracy, while their forms and materials are not at 

 the same time obvious, that a description of them is 

 absolutely necessary. Without great care in the form 

 and workmanship, and in the choice of substances for 

 many of these tools, the work becomes difficult, or te- 

 dious, or impossible; or if it is executed with much 

 unnecessary labour, the performance of the fireworks is 

 incorrect, or sometimes even fails altogether. In de- 

 scribing these objects we shall pass slightly over those 

 which are most easily made, for the purpose of explain* 



VOL, XVII. PART I. 



Of the 

 moulds, 

 rammers, 

 and other 

 utensils re- 

 quired in 

 making 

 fireworks. 



in more particularly the nature and construction of 

 those that require greater nicety and more car*. 



The fundamental utensil, in every sense cf the word, 

 required in making fireworks, is a stout block of wood CCCCLXXII. 

 cut across the tree, such as that ued by butchers for Fig. 1. 

 chopping blocks. More than one of these will of course 

 be wanted, either where there is much work to be done, 

 or many sizes of cases required. It is very convenient 

 to have cavities sunk in those blocks, fitted to contain 

 the bottoms of the moulds, to be afterwards describ- 

 ed, by which means they are the more easily kept 

 steady in driving. 



The mallet required for driving is made of beech, of 

 a cylindrical form, with a handle prolonged from the 

 axis of the cylinder, having a knob or projection at the 

 end to prevent it from slipping out of the hand. One 

 side of the cylinder should be shaved off for the sake 

 of obtaining a flat surface. Different sizes are also re- 

 quired for different kinds of work ; as, with the heavy 

 one?, it would be as impossible to drive small cases, as 

 it would he lo drive large cases with light mallets. 

 None, however, need be less than half a pound in 

 weight, and the largest need not exceed six pounds. A 

 series consisting of half a pound, two pound*, four, and 

 six, is quite sufficient. 



Such are the materials required for driving. But it 

 is not necessary that all fireworks should be driven by 

 the blows of a mallet, and there are indeed many that 

 will not admit of it. In the smallest classes of serpents 

 and lights, for example, it is more convenient and 

 quicker to drive without the mallet. As a substitute, 

 a metallic ramrod may be adopted ; and by making the 

 head sufficiently heavy, as much force as is required 

 may be given with more convenience, while the work 

 also proceeds very quickly. These rammers are best 

 made of gun metal; and it is necessary that they should 

 be very smooth and true. The sizes must be propor- 

 tioned to those of the former and wooden rammers, 

 hereafter to be described. 



The Former. Only two shapes for these are requir- The for- 

 ed, namely, spherical, and cylindrical. The first, how. raer. 

 ever, are only wanted for the construction of paper 

 shells for mortars : the latter belong to all other fire- 

 works of whatever nature. One, or at most two sizes 

 are sufficient for the spherical formers, and their dia- 

 meters may be computed for a coehom, or 5$ inch 

 mortar, and for an 8 inch one ; as it is not convenient 

 to throw larger shells, on account of the weight and 

 size of the mortar, and as the difference between the 

 royal and coehorn mortars, which is only an inch, ren- 

 ders it unnecessary to adopt both. 



As the thickness of the shell for the 8 inch diameter 

 cannot well be less than an inch when completed for 

 firing, six inches will be the diameter of the spherical 

 former for this class of mortars. For the coehorn shell 

 ^ths of an inch is a sufficient thickness ; and the former 

 tor this size will therefore be 4 inches. These spheres 

 are to be made of beech, and they must be turned very 

 true and polished. A hole is also to be bored in them 

 of an inch in diameter, to receive the stand on which 

 they must be placed when used, and by which also the 

 fuse hole is determined. 



The cylindrical formers require to be of every dia- , 



meter that may be wanted, from the sixth of an inch 

 up to six inches, or even to a foot ; as there is no limit 

 to the sizes of fireworks, either for number or dimen- 

 sions, but the fancy of the operator. The best wood 

 for them, where they are made of wood, is beech ; and 



