Turris
(
τύρσις, πύργος). Any lofty building; a tower; a fort or
fortified place. The regular tower of fortification was either round or square, several
stories in height, with turrets (
pinnae) surmounting them, loop-holes
(
fenestrae) in the walls, and an arched entrance (
fornix) in the middle. A movable tower (
turris mobilis) was used
in sieges to protect the approach of the battering-ram to the walls. (See
Aries.) Such a tower was sometimes several stories in height, and could
be raised or lowered in order to allow the troops in it to scale the walls (
Livy, xxi. 11; Vitruv. x. 13). When elephants were used in battle, they
carried a sort of tower on the back filled with soldiers (
Livy, xxxvii.
40). For the towers on the decks of ships, see
Navis.