(12) The trench surrounding the obelisk, by means of which it was intended to separate it from the surrounding rock, is of most peculiar form, the effect being a series of parallel and equidistant vertical cuts, as if it had been made by a gigantic cheese-scoop. Plate III, no. 1, shews the structure of the sides and bottom of the trench. Its width averages 75 cent., and its depth about two-thirds that necessary to extract an obelisk of square section. Down the division between each concave “cut” a red line was drawn, it appears, by a plumb-bob with its string dipped in ochre (section 44). These lines are not continuous, but have been projected down from time to time as the level of the work became lower. The average distance between the vertical red lines is 29.9 cm., there being very little variation between examples. These appear to be feet, and the unit the double-foot. This is discussed in section 18. It will be noticed in plate III, no. 1, that distinct horizontal marks are visible along the wall parallel to the bottom of the trench; these shew how uniformly the work was kept at the same level. The aspect of the bottom of the trench is so well shewn as not to need a description. When the whole trench is examined, the divisions _across_ the bottom of the trench seem to run in pairs; it is difficult to define where the resemblance between each pair lies, but it is very clear, and I noticed it almost as soon as I began work. A clearer feature is the division between the depressions at the bottom of the trench separating each into a north and a south half, shewing that the work was done from each side of the trench alternately. At irregular intervals, and not parallel either to the top of the obelisk or to each other, are red and black lines. They occur all over the walls of both trenches and on the sides of the obelisk itself. On plate I, no. 6, I give a diagram of the lines on the rock face U V, where they are clearest and most numerous. The only explanation I can give for them is that they are merely lines from which to measure from time to time the depth to which the trench had reached. A feature of the surrounding trench is that there are no corners—everything is rounded; neither are there any traces of the marks of wedges, which are quite unmistakable (see plate III, no. 2); besides, it is not practicable to use a wedge unless one has to remove a part from the side of the parent rock. Chisels also leave sure traces; examples of fine pointing are seen in plate III, no. 2, and rough dressing on plate III, no. 4 (which was taken in the quarries of Shellâl). There are no traces of chisel-work in the trench at all, and not a trace of any copper implement was found during the clearance of the obelisk. We are therefore forced to the conclusion that the large balls of tough greenish-black stone, found in such profusion round the obelisk and all quarry work at Aswân, must have been the tools employed. {12}