CÖHORN, Menno, Baron de, the Vauban of Holland, and the contemporary as well as rival of the celebrated French engineer, was born at Lecuwarde, in Friseland, in 1641. His father, an officer of distinguished merit, early inspired him with a taste for military science; and having studied mathematics, in which he made great proficiency, under his uncle Fullenius, professor at Franeker, he entered the service with the rank of captain, at the age of only sixteen. In 1673, he attracted notice at the siege of Maëstricht, and afterwards distinguished himself so much in the bloody battles of Sener, Cassel, St Denis, and Fleurus, that he was promoted to the rank of colonel. In the campaign of 1675, he performed an important service at the siege of Grave, by successfully employing the means which he had invented for crossing the fosses of fortified places, and thus carrying a bastion without a counterscarp, the access to which was defended only by the river Meuse; a service for which he received, on the spot, the warmest commendations of Vauban. At a subsequent period Cò’horn ably applied his theory of fortification to the fortress of Coverden, the works of which he directed; and when war broke out in 1689 between Holland and France, he distinguished himself by new exploits. At the siege of Namur he was opposed to Vauban, and at the head of his own regiment defended Fort William, which he had himself constructed, in the most gallant and determined manner; but he was at last compelled to yield to superior force, and surrendered the work to his great rival. He had his revenge, however, in 1695, when he participated in the capture of the same place, which had been fortified by himself, but which Bouffiers was unable to hold out against King William. The alternate taking and retaking of Namur, under the direction respectively of Vauban and Cò’horn, is considered as illustrative of the different styles or systems of these celebrated engineers; Vauban employing no more artillery than was absolutely necessary, using his influence to moderate the ardour of the troops, whom he never permitted to advance except under the cover of works, and placing his glory in the most rigid economy of life; whilst Cò’horn, on the other hand, accumulating artillery of all kinds, and sacrificing every thing to the desire of abridging the siege, by striking the besieged with surprise and terror, was equally prodigal of means and of men. “Vauban avait cerné, reserré, coupé, morcelé les assiégés; Cohorn ne s’était occupé que de les accabler. C’était la force substituée à l’industrie, [7:7:30]ou plutôt l’industrie employée à multiplier les moyens de destruction.” In 1702, Ccihorn, now appointed lieutenant-general, published in Dutch h is New Method of Fortifying Places, Leewarde, folio; a classical work, which, several years afterwards, was translated into French under the title of Nouvelle Fortification, tant pour un terrain bas et humide que sec et élevé. Hague, 1706, 1711, 1713, 8vo. In 1703 Cöhorn conducted several sieges according to the system above described, forced Bonn to capitulate in the space of three days, and performed other important services. But his active career was now approaching to a close, for, on the 17th March 1704-, he died of apoplexy, at the Hague, whither he had gone, at the invitation of Marlborough, to concert measures with that great commander for opening the ensuing campaign. Bergen-op-Zoom, which was fortified by Cöhorn, is generally and justly considered as his masterpiece, and was for many years believed to be impregnable; but, to the surprise of all Europe, it was taken by the French under Lowendahl in 1647, though not without suspicion of treachery on the part of the garrison, which certainly made a very feeble defence; and, in 1814, an attempt to carry it by a coup-de-niain, planned by the gallant Lord Lyndoch, had nearly succeeded, and, in truth, misgave only by an extraordinary accumulation of adverse accidents, to which indeed night attacks are all more or less exposed.