TREBUCHET, engine for propelling large stones, very similar to the mangonel, but whose counterpoise was suspended from the beam instead of being fixed to it. TRENCH, road sunk in the ground, the earth being thrown up on one side only, or on both sides, for enabling the approach of places under cover. TRENCH-SHELTER, temporary defence, consisting of an exterior epaulment made with the earth taken from a trench, in a way to shield the soldiers upon a front, around a camp or a post, and enable them to fire under cover. The trench-shelter is destined to play an important part since fire-arms have acquired a long range and a rapid discharge. The Romans, in their day, made use of trench-shelters in the field. VINEA (Latin), a wooden mantlet, also a timber gallery, set up perpendicularly to the _agger_, and which affords approach to the platform under cover. The wooden towers intended to attack the ramparts of the besieged were rolled forward on these wooden galleries (see p. 83). THE END. End of Project Gutenberg's Annals of a Fortress, by E. Viollet-le-Duc