Terre-plein. In field fortification, the plane of site or level country around a work. The terre-plein of the rampart in permanent fortification, is the broad surface which remains after constructing the parapet and banquette.
Terror, Reign of. See [Reign of Terror].
Tertiate. In gunnery, is to examine the thickness of the metal of a piece of artillery, in order to judge of its strength. This is usually done with a pair of caliper compasses. To tertiate a piece of ordnance, is to examine the thickness of the metal, in order to judge of its strength, the position of the trunnions, etc.
Teschen. A town of Austrian Silesia, on the right bank of the Olsa, 38 miles east-southeast of Troppau. Here, in 1779, a treaty of peace was concluded between Maria Theresa and Frederick II., by which the dispute of the Bavarian Succession was brought to an end.
Testri (Northern France). Pepin d’Heristal, invited by malcontents, here defeated and captured Thierry III., king of Austrasia, and established himself as duke, 687.
Testudo (Testude). In ancient warfare, was a defensive arrangement of the shields, by means of which a body of men advancing against a wall for assault or mining, sought to protect themselves from the darts and weapons of the defenders. The men standing in close order, joined their shields above their heads, the edges overlapping, until the whole resembled the shell of a tortoise (testudo). The name was also applied to a machine moving on wheels, and roofed over, under which soldiers worked in undermining or otherwise destroying the walls in a siege.
Tête-de-pont (Fr.). A field fortification in front of a bridge, to cover the retreat of an army across a river. They are generally formed in the shape of a redan, a system of crémaillères, horn- or crown-works, or portions of star-and-bastioned forts. In order to add to the defense of tétes-de-pont, reduits have been constructed within them, and the dimensions of their parapets are in general made larger than those of any other field-work, on account of their great importance. Sometimes the area inclosed by a tête-de-pont is temporarily made use of as a depot for the stores necessary for the troops, in which case its tracing should present a strong point of defense, well provided with artillery, and affording in several points egress. The tracing which has been found the best for the passage of extensive trains of wagons and artillery, as well as columns of troops, is formed of crémaillères, extending in such a manner as to inclose a large area, and leaving behind each a passage well guarded and secured by second crémaillères, fronting the passage, and forming a second line. Additional strength will be given to têtes of every kind by constructing small redans or batteries on the opposite side of the river, the fire from which may defend the ground in front of the salient, and flank the faces of the tête-de-pont.
Tettenhall (Staffordshire). It was probably at this place, then named Testenheal, that the Danes were defeated by the Anglo-Saxons sent against them by Edward the Elder, August 6, 910.
Tetuan. A seaport town on the north coast of Africa, 22 miles south of Ceuta. It was taken by the Spaniards under O’Donnell, February, 1860; and the treaty of Madrid, by which the city was evacuated in favor of the Spaniards, was concluded October 30, 1861.
Teutoburg Forest. Probably situated between Detmold and Paderborn, in North Germany, where Hermann, or Arminius, and the Germans defeated the Romans under Varus with great slaughter in the year 9. This defeat was regarded at Rome as a national calamity.