If we multiply up the unit of .069 metre we get:
| .069 × .25 | = .01725 |
| .069 × .5 | = .0345 |
| .069 × 1 | = .069 |
| .069 × 2 | = .138 |
| .069 × 3 | = .207 |
| .069 × 4 | = .276 |
| .069 × 5 | = .345 |
| .069 × 6 | = .414 |
| .069 × 7 | = .483 |
| .069 × 8 | = .552 |
| .069 × 9 | = .621 |
| .069 × 10 | = .690 |
| .069 × 11 | = .759 |
| .069 × 12 | = .828 |
It will be seen from this that the unit, if it is a unit, is not a factor of the royal Egyptian cubit of .525 m., nor of the small cubit of .45 m., neither is it connected with the Egyptian finger of .0187 m. Further, it bears no relation to the obelisk single- or double-foot. Since we have no information as to whether this unit of .069 metre is a sixth, eighth, tenth or twelfth of a foot or cubit, it is rather unwise to try to reconcile it with the known Egyptian units, as, even during the same reign, the influx of foreign measures and the variations of the native measures would enable us to find an equivalent to almost any unit that could be imagined.
I am aware that DECOURDEMANCHE, in the Annales du Service, volume XII, page 215, gives the measure .06925 as a palm of the “lapidary” cubit of .4155 m., but I place very little reliance on this cubit, as it only explains the dimensions of one tomb measured by Amélineau at Abydos, and this tomb can be equally well rendered in the royal cubit system.
The relation of the obelisk foot to the royal Egyptian cubit is seen in the following table:
| metres. | ||
|---|---|---|
| Finger | (1) | .0187 |
| Palm (also = 3 inches) | (4) | .075 |
| Common foot | (16) | .300 |
| Common cubit | (24) | .450 |
| Royal cubit | (28) | .525 |
It will be noticed that the actual measurements of the obelisks, both the original and the later project, very largely depend on the royal Egyptian cubit of .525 metre. The height of the large obelisk does not. Probably the order was for as large an obelisk as possible. The dimensions of even royal cubits are:
| cubits. | |
|---|---|
| Base of large obelisk | 8 |
| Base to black line π | 4 |
| Base of later project | 6 |
| Height of pyramidion of later project | 10 |
Most of the remaining measurements, except the base of the pyramidion of the later project, depend on the rock rather than on the wish of the designers. Since the obelisk is still in a rough state I cannot give many accurate measurements from which the cubit can be found precisely. The two most accurate measurements are the base of the original obelisk and the base {20} of the later project. The former measures 4.20 or 8 cubits of .525 m., and the latter measures 3.15 or 6 cubits of .525 m.
As to the explanation of the scales on the quarry-face, though much is still obscure to me, I believe the lower series of vertical scales are the records of the work of the last shift employed in cutting out the trench by which the monument was removed, and the semi-effaced series on a higher level the records of preceding shifts. It seems likely that the red chains are fortuitous, and do not represent any particular unit, but marked the position of the tip of a 3‐cubit rod, when standing on the bottom of the trench, thus recording the depth reached by each party of workmen at definite intervals of time, possibly after every two days’ pounding.