ABSTRACT
The longitudinal walls of the Parthenon are composed of 19 rows of marble blocks. The first bottom row, called orthostate, is composed of blocks with average dimensions 1.44 m length, 0.55 m depth and 1.15 m height. The last row is composed of architrave with average dimensions 2.44 m length, 0.5 m depth and 1.04 m height. The intermediate 17 rows are built with smaller marble blocks (length 1.22 m, height 0.52 m). The even-numbered rows are composed of two lines of blocks, disposed with their long axis parallel to the axis of the wall. Many blocks of the external line, facing north, are conserved, whereas the internal ones, facing south, are lost. In the odd-numbered rows the blocks are placed perpendicular to those of the evennumbered rows (Fig. 1). The blocks are horizontally connected with clamps and vertically with dowels (Fig. 2). The main actions that affected the mechanical history of the walls of the Parthenon are the fire of 267 A.D. and the explosion of 1678 A.D. during the siege of Athens by the Venetians. The latter caused the collapse of the larger part of the walls.
