We may also remark, that we have given some of the more common, or general properties of the substances, employed in the composition of fire-works, without going into that detail, which belongs exclusively to works that treat of Chemistry. It was neither our design, nor have we given, for the reasons thus stated, _all_ the chemical characters or properties of the substances so employed; and, therefore, have confined ourselves, generally speaking, to an enumeration of such properties as are connected with the subject, or are indispensably necessary to be known, before a rationale of the causes and effects can be understood. It was our intention to accompany the work with plates, exhibiting the arrangement, &c. of fire-works, which, there can be no doubt, would have facilitated in particular the knowledge of forming, and arranging, certain pieces of fire-work; but, on second reflection, as such illustrations were connected more with fancy exhibitions, and have little or no relation to Military Fire-works, the most useful branch of Pyrotechny, we were finally of opinion, that the addition of plates would greatly enhance the price, without advancing or adding to the value of the work. If, however, a second edition should be required, various figures in illustration of particular subjects may be added, either with a distinct explanatory chapter, or a reference from the articles themselves, with the necessary explanation, to the figures respectively. It would require at least twenty-five plates to include all the figures we originally intended to have introduced. Before concluding this introduction, it remains for us to remark, that, in forming this work, we consulted a variety of authors, but with little advantage, except some French works, which we shall notice. Chaptal (_Chimie Appliqué aux Arts_;) Bigot (_Artifice de Guerre_;) Morel (_Feux d'Artifice_;) Thenard (_Traité de Chimie_;) Ruggeri (_Pyrotechnie Militaire_;) MM. Bottée and Riffault (_Traité de L'Art de Fabriqué la Poudre à canon_;) Peyre (_Le Mouvement Igné_;) Biot (_Traité de Physique_, _Recherches Experimentales et Mathématique_, _sur les mouvement des Molecules de la Lumiere_, _&c._;) M. Duloc (_Theorie Nouvelle sur le Mechanisme de l'Artillerie_;) the _Dictionnaire de l'Industrie_; the _Dictionnaire Encyclopedique des Arts et Metiers Mecaniques_, article _Art de L'Artificier_; _Œuvre Militaire_; _Archives des Découvertes_; _Système des Connoissances Chimiques par A. F. Fourcroy_; _Aide-Mémoire a l'usage des officiers d'Artillerie de France_. We examined various authors in English; and with regard to the origin of inventions, we found the learned, and valuable work of professor Beckman (_History of Inventions_) very useful, and likewise James's _Military Dictionary_. To the _Encyclopedia Britannica_, we are indebted for many interesting facts, and some extracts on fire-works for exhibition.