On the subject of mining, we consulted the _Treatise on mines for the use of the Royal Military Academy_, by Landmann. We deem it necessary to observe, that, in collecting our formulæ for military fire-works, although we have sometimes extracted from the Strasbourg _Memoir_, the _Bombardier and Pocket Gunner_, and the _Military Dictionary_ of Duane and James, we have generally followed Bigot; as the formulæ which he gives for the preparation of Military fire-works have been approved by the French government; and where any thing of importance occurred in Ruggeri, we have, for the same reason, extracted such formulæ from that author. As respects the turtle, torpedo, and catamarin, submarine machines, it appears that Bushnel (_Trans. Am. Phil. Soc._) claims the originality of the discovery from the date of his invention, although similar contrivances had long ago been suggested. Fulton's improvements, in the torpedo, are deserving of particular attention; but it is plain, that the Catamarin of the English is the same in principle and application as Fulton's torpedo, and that Fulton deserves the merit of it. Congreve, if we believe Ruggeri, was not the inventor of the rocket, which bears his name; for, according to him, it was invented about the year 1798 by a naval officer at Bourdeaux. It is certain, however, it was neither much known, nor used before the attack on Copenhagen. It is certain that the present incendiary fire-stone was taken from the recipe for fire-rain contained in the military work of Cassimir Siemienowicz, or that the fire-rain gave rise to a similar preparation. The idea of the _pyrophore_, mentioned in the _Archives des Découvertes_, must have originated from the use of the powder-barrel, and of similar means of defence. We might enumerate many other inventions, which owe their origin in the same way. A SYSTEM OF PYROTECHNY. CHAPTER I. PYROTECHNY IN GENERAL. _Sec. I. Definition of Pyrotechny._ Pyrotechny is defined the doctrine of artificial fire-works, whether for war or exhibition, and is derived from the Greek, πυρ _fire_, and τεχνη _art_. In a more general sense, it comprehends the structure and use of fire-arms, and the science which teaches the management and application of fire in several operations. _Sec. II. General theory of Pyrotechny._ In the composition of artificial fire, various substances are employed, having different properties, and designed to produce certain effects characterised by particular phenomena. These substances are either inflammable, or support the combustion of inflammable bodies. As pyrotechnical mixtures are differently formed, and of various substances, the effects are also modified, although combustion, under some shape always takes place. Combustion is either modified, retarded, or accelerated; and in consequence of the presence of certain substances, different appearances are given to flame.