BATTER  , an architectural

term of unknown origin, used of the face of a wall which is slightly inclined to the perpendicular . It is most commonly employed in retaining walls, the lower courses of which are laid at right angles to the batter, so as to resist the thrust of the earth inside . For aesthetic reasons it is often adopted in the lowest or basement porticos of a great building . From a historical point of view it is the most ancient system employed, as throughout Egypt and Chaldaea all the temples built in unburnt brick were perforce obliged to be thicker at the bottom, and this gave rise to the batter or raking side which was afterwards in Egypt copied in stone . For defensive purposes the walls of the lower portions of a fortress were built with a batter as in the case of the tower of David and some of the walls built by Herod at Jerusalem . The Crusaders also largely adopted the principle, which was followed in some of the castles of the middle ages throughout Europe .