9.The cut grooves could not have been produced by a rotating blade such as found on a circular saw. A rotating blade does not make scratches of variable radius. Even if the blade was four meters in diameter we would expect to see a pattern of circular scratches across the cut face of two meters radius, but this is not the case. The only other uni-directional cutting means that is at least feasible is an abrasive-fed cable or band saw, but the degree of mechanization needed for these devices does not fit well in the Fourth Dynasty of ancient Egypt. The remaining possibility is that these scratches were produced by a reciprocating straight blade. In fact, the type of grooving we see is known to be produced by a reciprocating,a brasive-slurry-fedb lade having a notched edge.

10. Perhaps a finer adjustment means was used, but in any case the actual feed rate was probably determined by gravity. That is, once the swinging blade made contact with the work, it guided itself across the cut, its advancement into the block determinedb y its weight rathert han the suspension ropes. Other ropes attached to the blade ends allowed the blade to be pulled through the cut as it swung back and forth with a stroke of about one meter. The cutting medium was probably quartz sand. It is harder than any of the minerals in the basalt, and perfectly capable for the job. Either the cutting occurred under water and sand was poured over the blade or a water/sand slurry was continually fed to the cut. The latter procedure would allow better visibility of the work.

11. Conclusions
If the procedure just hypothesized is accurate then the following can be concluded:

• 1) The invention of the swinging drag saw can be traced back more than two thousand years beyond its previous date.
• 2) The degree of mechanization indicated by this operation is somewhat more advanced than general views of the pyramid builders' technology level now hold.
• 3) The sawing done in this place represents a sophisticated operation of a mature industry.