Christian Ubertini


Place / year: Elephantine, Egypt / 1999-2000
Organisation: Swiss institute for archeological reasearches in Egypt
Function: Architect

View of a sandstone wall with blocks perfectly calibrated

View of the contact faces of the blocks

Zoom on a joint between two blocks with the small saw cuts visible under the vertical joint

Saw cut marks, visible on the upper face of the blocks

Saw cut marks, visible on the upper face of the blocks

Phasing showing the installation process of a new blcok on a wall under construction

Restitution example of two rows of blocks confirmed by the saw cut marks visible on the underneath row, and perfectly matching with the blocks of the above row.


Building techniques in Egyptian Architecture have always fascinated scholars and visitors by the quality of the stone work and masonry systems. But surprisingly, the study of building techniques is still at its beginning and a lot of processes remain unexplained and many tool marks are today being misinterpreted. One of the processes that still needed to be clarified was the method used by stone builders to implement the perfect adjustment of the joints between the blocks, which can be seen on Egyptian temple throughout all periods.

Several observations on sandstone masonries of the Ptolemaic and Roman periods (330 BC - 100 AD) and particularly the analysis of specific tool marks give a better understanding of the block's adjustment process.  One of this tool marks is visible on the upper side of the stone like tiny cuts (C), carved perpendicularly to the stone casing. These marks are marks left by a saw used by stone builders to cut the blocks’ joints. A closer observation at still in situ masonries shows that the cut leans exactly against one block and its thickness lies, consequently, under the other block. This situation can be explained as follows:

  1. The new block (NB), already cut and calibrated to fit with the other joint, was brought in place and leaned against the already installed block (AIB).
  2. In order to adjust both blocks perfectly, their common joints were cut simultaneously with a saw (S) which traces can still be seen on the joint.
  3. Once the saw had passed all the way through, the blade left inevitably a cutting mark on the underneath block (UB).
  4. The final touch was to push the block against the other one to fill the void left by the saw’s blade re-covering by the same way the cutting mark.

This demonstration opens a new prospective for architectural studies. In fact, in a still standing monument, the observation of saw cut marks allows to determine which block was led before which one, and therefore allow following, stone by stone, the progress of the building work. While for the study of a scattered material, the lecture of saw cut marks on single stone gives precise information about the dimension and location of the block which was set on top of it, confirming the vertical connection between two scattered blocks.

Christian Ubertini 2001
Schweizerisches Institut für Ägyptische Bauforschung und Altertumskunde in Kairo

Selected bibliography