The average width of the trench is about 0 m. 75 cent.; the work may have been measured taking into account a minimum width, but this is not necessarily the case, as in certain places, the width of the trench gets smaller and smaller as it gets deeper, and then suddenly opens out again. In any case I imagine that the workmen would find it false economy to narrow the trench too much, as the cramped position would make the work go more slowly. I suggest that the reason for the occasional narrowings is that one party knew that their spell was coming to an end at a certain level, and finished it quickly, knowing that someone else had to continue the deepening. It will be noticed that the top-dressing, as seen at the pyramidion, plate IV, no. 1, and the butt-end of the obelisk, is less regular than the pounding work in the trench; it seems that, with more space at their disposal, the workmen were given an area to pound, and left to arrange their method of doing it. (15) As to the time which would have been taken to complete the trench, it is interesting to get a rough approximation. Assuming that, with rammers, the men can extract 8 millimetres in an hour in each quarter of their double-foot task, then the time taken to complete the trench, with an extra metre for undercutting, will be that of working it at its deepest part, that is to a depth of 4.2 + 1.0 metre, and will equal (4 × 5.2)/(.008 × 12 × 30) months of twelve hours per diem = 7.22 months. Before leaving the subject of time taken, we might apply this calculation to the obelisk of Ḥatshepsôwet, assuming that it was detached in much the same way. Here the deepest part of the trench is 2.40 + .75 metre[8]; then the time taken would have been: (4 × 3.15)/(.008 × 12 × 30) = 4.4 months. {15} [8] Since the obelisk is smaller. It is recorded by the queen that “they are of one block of enduring granite, without seam or joining. My Majesty exacted work thereon from the year 15, the first of Machir (6^{th} month), until the year 16, the last of Mesore (12^{th} month), making seven months of exaction in the mountain.” Allowing for undercutting and a certain amount of top clearance, our calculation seems within the bounds of reason. During the work of trench-pounding, the top-dressing, embankment preparing, and clearing for the exit of the obelisk would be carried on. {16} CHAPTER III. THE UPPER QUARRY-FACE. (16) At the south-west corner of the obelisk there is a kind of platform, sloping down southwards towards a vertical face of rock. Plate II, no. 2, shews the obelisk with the platform at the right, and plate V, nos. 1 and 2 shews the rock face viewed from below the north side of the obelisk, and from directly opposite it. A detailed drawing of the markings on the quarry-face is given on plate VI.