Demonstration. In military operations, is an apparent movement, the chief object of which is to deceive the enemy, and induce him to divide his force, as if to meet dangers from various quarters. When thus divided and weakened, he may be attacked with greater chance of success.
Denain. A village of France, department of the North. It is celebrated in history as the scene of the decisive victory gained in 1712 by Marshal Villars over the allies commanded by Prince Eugène.
Denbigh. The capital town of the county of the same name, North Wales. In ancient times it was a place of great military importance. The castle was gallantly held by Col. William Salisbury for the king during the civil wars of the revolution, but finally surrendered to the Parliamentary forces under Gen. Mytton.
Dendermonde. A town of Belgium, in the province of East Flanders. It is fortified, and has a citadel dating from 1584, and possessing the means of laying the surrounding country under water in case of an attack. Louis XIV. besieged it in vain in 1667, but Marlborough, aided by a long drought, succeeded in taking it in 1706.
Denmark. A kingdom of Northern Europe, which, with Sweden and Norway, was originally called Scandinavia. In ancient times it was occupied by a fierce and warlike people, whose principal occupation was piracy. In 832 the Danes landed in England, and there established two kingdoms, and two centuries afterwards the conquest of England was completed by Canute, king of Denmark. In the 15th century Christian I. connected Norway, Sleswick, and Holstein with the crown of Denmark, but in consequence of siding with Napoleon, Denmark was obliged to cede Norway to Sweden in 1814. In 1848 Sleswick and Holstein revolted, the duchies being aided by Prussia and other powers of the Germanic Confederation, who, however, concluded a peace on their own account, July 2, 1850. The duchies continued the war, were defeated at Idstet, July 25, 1850, and peace was restored by the intervention of the powers in January, 1851. Hostilities again commenced in 1863, and were terminated by the peace of Vienna in 1864, Denmark renouncing all claim on Sleswick-Holstein.
Dennewitz. A small village in the province of Brandenburg, Prussia. Here was fought, on the 6th of September, 1813, a battle between 70,000 French, Saxons, and Poles, commanded by Marshal Ney, and 45,000 Prussians, under Gen. Tauentzien. Both armies more than once drove each other from their positions, but the Prussians finally prevailed, and Ney gave orders to retreat. At this moment Bernadotte, crown-prince of Sweden, appeared at the head of a large army, and turned the retreat of the French army into a complete rout.
Denonciateur (Fr.). In a general sense, may not improperly be called a military informer. So rigid indeed were the regulations (even in the most corrupt state of the French government) against every species of misapplication and embezzlement, that if a private dragoon gave information to the commissary of musters of a troop horse that had passed muster, having been used in the private service of an officer, he was not only entitled to his discharge, but received, moreover, 100 livres in cash, and became master of the horse and equipage, with which he retired unmolested. The officer was summarily dealt with.
Densimeter. An apparatus for obtaining the specific gravity of gunpowder by immersing it in mercury. It consists of an open vessel containing mercury, a frame supporting a glass globe communicating by a tube with the mercury in the open vessel, and joined at top to a graduated glass tube, which communicates by a flexible tube with an ordinary air-pump. Stop-cocks are inserted in the tubes above and below the glass globe, and a diaphragm of chamois-skin is placed over the bottom orifice and one of wire cloth over the top orifice of the globe. The arrangement allows the globe to be filled with mercury to any mark on the graduated tube, or with gunpowder and mercury. The globe can be taken off and weighed in both cases. The specific gravity is obtained from the relation between the weights in the two cases.
Density. The density or specific gravity of gunpowder is one of its most important properties. In the form of dust, the velocity of combustion increases rapidly with the density up to about 1.60, when it decreases. In grained powder the velocity of combustion decreases as the density increases. For English or American powder this velocity is about four-tenths of an inch per second. For French and most of the continental powders, which are less dense than the English, it is about forty-eight-hundredths of an inch. The excellent preservative qualities of English and American powders are largely due to their high densities,—the standard being about 1.75. A certain degree of density is absolutely essential to grain powder to prevent the inflamed gases from penetrating the pores of the powder and flashing off the whole mass to the destruction of the gun. In the manufacture of powder the density depends, first, upon the amount of trituration to which the ingredients are subjected in the incorporating mill; second, upon the pressure employed to form the cake; and, third, upon the degree of moisture it contains when subjected to these operations, particularly the last. The pressure-gauge is not a reliable measure of the density given to a powder, though a good indication of the hardness, with which density must not be confounded. Dry powder meal offers a great resistance to compression, but becomes very hard,—the work being consumed in consolidating the surface particles. To obtain uniform density a certain amount of moisture is necessary to assist the particles in their movement. As much as 6 per cent. of moisture is used in making prismatic powder.
Department Commander. See [Geographical Department, Commander of].