Coehorn

Letters exchanged by Marx and Engels on January 14, 1858 show that originally it was Marx who intended to write this article. But owing to lack of time he could not obtain the necessary sources, whereas Engels had comprehensive material on Coehorn collected when studying problems of military history. Engels therefore undertook to write the article. No precise data is available when he wrote it. It might have been written with "Camp" and "Catapult" and finished by February 18 (see Note 310).

Coehorn, or Cohorn, Menno van, baron, a Dutch general and engineer, born in Friesland in 1641, died at the Hague, May 17, 1704. At the age of 16 he received a captain's commission, distinguished himself at the siege of Maestricht, and afterward at the battles of Senef, Cassel, St. Denis, and Fleurus.^[1] During the intervals of active duty he devoted much attention to the subject of fortification, with the view of equalizing the chances between besiegers and besieged, the new system of his contemporary Vauban having given great advantages to the latter. While comparatively a young man he gained a name as an engineer, and by the time he had reached middle life was recognized as the best officer of that arm in the Dutch service. The prince of Orange promised him a colonelcy, but being rather remiss in fulfilling the pledge, he retired in disgust with the intention of offering his services to the French. His wife and 8 children, however, were arrested by the order of the prince as hostages for his return, which quickly brought him back, whereon he received the promised rank, and was afterward appointed, successively, as general of artillery, director-general of fortifications, and governor of Flanders.

His whole life was spent in connection with the defences of the Low Countries. At the siege of Grave, in 1674, he invented and for the first time made use of the small mortars, called cohorns, for throwing grenades, and in the succeeding year elicited the applause of Vauban by successfully crossing the Meuse, and carrying a bastion which was considered as protected by the river. After the peace of Nimeguen (1678),^[2] he was employed in strengthening various already strong places; Nimeguen, Breda, Mannheim, since dismantled, and Bergen-op-Zoom attest the value of his system. The last-named place he considered his masterpiece, although it was taken after a long siege in 1747, by Marshal de Lowendal. During the campaigns from 1688 to 1691,^[3] he was in active service. The siege of Namur, in 1692, gave him an opportunity to test his system against that of Vauban, for these two great engineers were there opposed to each other, Coehorn in defending a work which he had constructed to protect the citadel, and Vauban in attempting to reduce it. Coehorn made an obstinate defence, but being dangerously wounded, was compelled to surrender to his rival, who handsomely acknowledged his bravery and skill. He was afterward engaged at the attack on Trarbach, Limburg, and Liège, and in 1695 aided in retaking Namur. In the war of the Spanish succession^[4] he besieged successively Venloo, Stephensworth, Ruremonde, Liège, and in 1703 took Bonn, on the Rhine, after 3 days' cannonade of heavy artillery aided by a fire of grenades from 500 cohorns. Next he passed into Dutch Flanders, where he gained several successes over the French, and directed the siege of Huy. This was his last service, for he died soon afterward of apoplexy, while waiting a conference with the duke of Marlborough on the plan of a new campaign.

Coehorn's greatest work, Nieuwe Vestingbouw, was published at Leeuwarden, in folio, 1685, and translated into several foreign languages. His plans are mostly adapted to the Dutch fortresses, or to those which are similarly situated on ground but a few feet above water level. Wherever it was practicable, he encircled his works with two ditches, the outermost full of water; the inner dry, and usually of the width of about 125 feet, serving as a place d'armes for the besieged, and in some cases for detachments of cavalry. The theory of his system, both of attack and defence, was the superiority of a combined mass over isolated fire. Professionally, Coehorn was accused of wasteful expenditure of life, in which respect he contrasted unfavorably with Vauban, who was sparing of men. Personally, he was blunt, honest, brave, and a hater of adulation. He refused inducements offered by several foreign governments. Charles II of England knighted him. He was buried at Wijkel, near Sneek, in Friesland, and a monument was dedicated there to his memory.