Page:Encyclopædia Britannica, Ninth Edition, v. 9.djvu/455

 FORTIFICATION 441 Architettura Militare (1759), that several small bastions had been constructed in the preceding century, and that the ruin of a large bastion which had formed part of the fortifications of Turin, built for Duke Louis of Savoy, still existed in the royal gardens at that time. The bastions on the enceinte of Verona, built by the Italian engineer Micheli, in the year 1523, are generally supposed to be the oldest extant; and the next, probably, are those of the citadel of Antwerp, which were constructed for the em peror Charles V. in 1545, by the Italian engineer Paciotto D Urbino. These bastions are small, with narrow gorges and short flanks and faces, and are placed at great distances from one another, it being the invariable practice, at tho time when they were built, and for a considerable time afterwards, to attack the curtains, and not the faces of the bastions. Errard of Bois-le-duc was the first in France who laid clown rules respecting the best method of fortifying a place, so as to cover its flank. He was one of the principal officers of the engineers in ordinary to the king, a corps formed by Sully, who was grand master or master general of artillery in the reign of Henry IV., out of the best instructed and most experienced military men. This corps is now the Corps de Genie, and to this day maintains its scientific character. At the command of the minister, Errard wrote a book on the subject, which was published in 159 1, and in which the details of his method are explained. As a writer on fortification, he was preceded in France by Beril de la Treille, who published his work on fortifying towns and castles in 1557. Errard fortified inwards; and in the square, pentagon, hexagon, heptagon, and octagon he made the flank perpendicular to the face of the bastion ; but in the enneagon, and in polygons of a greater number of sides, he made it perpendicular to the curtain. In his method, however, the gorges are too small, the embrasures are too oblique, and the ditch is almost defenceless. This engineer constructed part of the enceinte of the citadel of Doutens, the citadel of Amiens, and some works at Mont- reuil and Calais. Antoine de Ville, who succeeded Errard, published a treatise, dated 1629, in which he completed much that his predecessor had only sketched, and rectified various defects in the method of the latter. He was employed under Louis XIII., and constructed new enceintes for Montreuil and Calais. His method of fortifying has been denomin ated by some the French Method, and by others the Com pound System (Systeme cl trait comjmse), because it united the Italian and Spanish methods, from the latter of which it differs only in having no second flanks and fichant lines of defence, and in not confining the flanked or salient angle of the bastion to ninety degrees. The leading maxims of De Ville were to place the flanks perpendicularly to the curtain, to make them equal to the demigorges, or a sixth part of the side of the interior polygon, and, in the hexagon and all higher polygons, to confine the flanked angle to ninety degrees. But this method is liable to nearly the same objections as that of Errard, as the embrasures are too oblique, especially in the polygons, and the ditch is ill defended. In 1645, sixteen years after the publication of De Ville s, appeared the treatise of the Comte de Pagan, which contained the development of a system that, in a short time, entirely superseded those of his predecessors. It was the Comte de Pagan who first disengaged the science of Fortification from a number of suppositions which custom had consecrated, and which, resting more on abstract mathematical reasoning than on practical experience, had hitherto retarded the progress of the art. This engineer served at twenty-five sieges with great reputation ; but having become blind at the age of thirty-eight, he was obliged to retire from the service, in which he had already obtained the rank (then second only to that of marshal of France) of tnareschal-de-camp, and he died six years after completing the treatise above mentioned. He had from his earliest years devoted himself to the study of mathe matics and fortifications, and he published several works on astronomy besides his celebrated work on Fortification. Pagan made the flank perpendicular to the line of de fence, in order as much as possible to cover the face of the opposite bastion ; and he devised a method of building casemates peculiar to himself. Vauban borrowed from Pagan the length of his perpendicular, and Allain Manesson Mallet, whose construction has found much favour, pro ceeded upon the principles Pagan had laid down. 1 The Mareschal de Vauban was born in 1633; and at the time of the Comte de Pagan s death, he had already acquired reputation at several sieges. Vauban followed up the principles suggested by Pagan, and em ployed them extensively, with consummate skill arid judg ment. He constructed 33 new fortresses, repaired and im proved 100, and conducted about 50 sieges. His extensive works, especially the treatise De I Attaqne et de la Defense des Places, published in 1737, speak for themselves. From these works have been compiled the systems which, in the military schools, are denominated Vaubau s first, second, and third systems of Fortification, and which the reader will find developed in the sequel. Had the genius of Vauban been applied to the discovery of a method for securing a perma nent superiority to the defence of fortified places, posterity would have been greatly indebted to him, and even human ity would have had cause to rejoice in such a triumph of military art. But, being engaged in the service of the most ambitious monarch of modern times, Louis XIV., he applied his great talents to forward his master s views, and perfected that irresistible system of attack 2 which has ever since been so successfully followed. Before his time the superiority was on the side of the defence ; but he so completely reversed the case that the success of an attack, conducted scientifically and with adequate means, has been until the present time a matter of certainty. 3 Vauban was no ordinary man in any sense. As the inventor of parallels in sieges, and of rico chet fire, he stands in the first rank of military engineers ; and as he conducted 53 sieges, and took part in 14G battles and skirmishes, it must be admitted that in respect of experience he stands in no inferior position. At fifty- five years of age he attained the highest honour of the French army, being created marshal of France ; yet amidst his stirring and successful military life he never ceased to turn to account the geometrical knowledge for which he was distinguished when a youth, and which had obtained for him the early notice of the Prince de Conde. His mind was never idle, and was constantly directed to pro jects of public utility, civil as well as military; and he left behind him records of such labours in 12 folio manuscript volumes, entitled Mes Oisiveten, a wonderful monument of his ability and industry. M. Minno, Baron de Coehorn, first a general of artillery, then a lieutenant-general of infantry, and ultimately direc- 1 Mallet constructed outwards, making in every figure or polygon the demigorge equal to a fifth part of the side of the interior polygon or figure, the capital of the bastion equal to a third part of the same side, the curtain equal to three-fifths or thrice the demigorge, and the angle of the flank equal to 98. The faces of the bastions and the flanks are determined by the lines of defence, which are razant. From these- data all the other lines and angles are easily found. 2 See his work De I AUaque et de la Dtfense des Places, passim. 3 The protracted siege of Sebastopol is no exception to this rule. The length of its resistance was due to the fact that the resources at the disposal of the allied armies did not suffice for its investment, and that the Russians were in consequence able to introduce at their plea sure reinforcements of men, material, and provisions; indeed, at times- they were more numerous than the attacking force. IX. 56