THE Petard, a, [Plate X, Fig. 3, 4.] is a machine made of braƒs, as the cannon; its figure is exactly that of the fruƒtum of a cone, or, as the chevalier de Saint Julien terms it, of a Spaniƒh hat; it is concave within, its height it commonly 10 inches, and its diameter at the top 7 inches, and at its bottom or aperture 10 inches; it has, like a cannon, a touch-hole in that part oppoƒite to its mouth, which may be conƒidered as its breech; as to its ƒize, it may be either bigger or leƒs, and in general it ought in this reƒpect to be proportioned to the effect it is intended to produce.
        The ordinary method of charging the petard is, to force into it as much fine powder as it will hold without being preƒƒed down, this powder is then covered with paper doubled, or a piece of old hat, the whole width of the bore, upon which is alƒo placed a kind of wooden plug, or bung, of the ƒame diameter with the bore of the petard, which is forced down upon the powder by ƒtriking it ƒmartly with a mallet, taking care however that it be not driven in ƒo forcibly as to bruiƒe the powder; the reft of the petard is then filled up with tow dip'd in bees-wax or pitch, and the whole is covered with a wax'd cloth.
        The petard has four handles, by which it is ƒtrongly faƒtened with bands of iron to a madrier, that is, a plank 2 or 3 inches thick, repreƒented by Fig. a. [Plate X, Fig. 3, 4] The madrier has on the ƒide oppoƒite to that on which the petard is placed, two iron bandages, which croƒs it diagonally, or from angle to angle; it has alƒo an iron hook, to faƒten the madrier to the place where it is to be fixed. For theƒe bands and hook ƒee figure d.
The petard is uƒed to break open the gates of towns and caƒtles, intended to be taken by ƒurprize.
        For this purpoƒe an approach is made to the gate, in ƒuch a manner as to prevent a diƒcovery, and with a ƒcrew, or ƒome other inƒtrument, the madrier is ƒaftened by its hook to the door intended to be broken open, which being done, the fuƒe of the petard is fired, and this being filled with a compoƒition that burns out ƒlowly, gives time to the petardier, or perƒon who fixes the petard, to retire; the fuƒe having fired the powder the petard is charged with, this powder preƒƒes the madrier againƒt the door with ƒuch violence, that it burƒts it open, or makes a breach in it.
        The buƒineƒs of a petardier is extremely dangerous, few officers, according to M. St Remy, returning from this expedition. For if the petard is perceived by the garriƒon, they will be ƒure to fire at the operator, either from the pieces planted over the gate, or thoƒe to the right and left, and ƒcarce ever miƒs him.
        The uƒe of the petard is not ancient, this machine being entirely a modern invention, according to the chevalier de Ville, firƒt diƒcovered and uƒed in France, from whence it has paƒƒed into other countries.
        Henry the 4th, being then only king of Navarre, ƒurprized Cabors, the capital of Quercy, with a petard in 1579, having made an eƒƒay of it ƒome time before, at a little caƒtle of Rovergue.
        The petard has been much more uƒed than at prevent, tho' places are not leƒs frequently taken by ƒurprize; it may, however, be uƒed with advantage on feveral occaƒions, and thoƒe who would know all the precautions neceƒƒary to render it ƒucceƒsful, may conƒult the chevalier Ville, who has treated the ƒubject as minutely as they can wiƒh.
        Before we leave this article we ƒhall obƒerve, that the petard is made uƒe of to throw great ƒtones into a town. M. Blondel gives an inƒtance of it at the end of his treatiƒe on the art of throwing bombs, which perhaps will not be diƒpleaƒing here, as it may ƒerve to give ƒome idea of a method of throwing bombs, in caƒes of neceƒƒity, even without the help of a mortar.

        "The Poles, ƒays M. Blondel, aƒƒiƒted with auxiliary troops of the emperor's under the conduct of the count de Souches, in 1659 beƒieged the town of Thorn, in Pruƒƒia, then held by the Swedes, and often threw in ƒtones of a monƒtrous ƒize, and great fragents of milƒtones and freeƒtones of 800 weight, without the uƒe of mortars, in the following manner.
        "In the beaten ground near the counterfcarp they ƒunk beds, exactly of the ƒize and figure of the ƒtone they intended to throw, made flat and level at the bottom, which was inclined towards the town, in ƒuch an angle as they judged it ought to have for the direction of their ƒhot. In the middle of this bottom they ƒunk another hole, ƒtill deeper, in form of a chamber, in ƒuch a manner as that the axis of this laƒt hole paƒƒing through the ƒtone's centre of gravity, was perpendicular to its bed, and the ƒame as its line of direction; they filled this hole with powder, if the earth was firm enough for the purpoƒe; and if not, they put in a petard of a ƒize proportioned to the weight of the ƒtone, which reƒting upon the flat ƒide of the madrier of the petard, or the ƒtopple of its chamber, was impelled by the whole force of the powder, which they lighted by means of a thread ƒteep'd in brandy, and the compoƒition of a fuƒe, and the ƒtone riƒing to a great height, fell into the town on the place intended, and broke to pieces all it met with in its fall.