Header and stretcher wall at Samaria. In this ancient method of wall construction, some stones—called stretchers—were laid parallel to the length of the wall. Others— called headers—were laid perpendicular to the wall’s length, so that only their short ends showed. By extending into the wall, headers provided added strength.
The trimmed edges and margins of the ashlars gave the wall builders clear guides for aligning the stones. The rough, protruding bosses within the margins seen here can be compared with the smooth, flat bosses of the Herodian ashlars to the left of the “straight joint.”