Free From Atlantis to the Sphinx by Colin Wilson

and concludes that the Egyptians must have possessed some tool that is totally unknown to, and unsuspected by, Egyptologists. It sounds, admittedly, too preposterous to suggest that they had some kind of electric drill. Yet when we consider Petrie’s comment about grooves ‘ploughed through the diorite’, it seems obvious that they must have had some means of making the bit spin at a tremendous speed. A potter’s wheel, with suitable ‘gears’, might just do it.
    In fact, a modern toolmaker, Christopher P. Dunn, studied Petrie’s book in an attempt to make sense of his descriptions, and in an article called ‘Advanced Machining in Ancient Egypt’, reached some astonishing conclusions. He comments:
    The millions of tons of rock that the Egyptians had quarried for their pyramids and temples—and cut with such superb accuracy reveal glimpses of a civilisation that was technically more advanced than is generally believed. Even though it is thought that millions of tons of rock were cut with simple primitive hand tools, such as copper chisels, adzes and wooden mallets, substantial evidence shows that this is simply not the case. Even discounting the argument that work-hardened copper would not be suitable for cutting igneous rock, other evidence forces us to look a little harder, and more objectively, when explaining the manufacturing marks scoured on ancient granite by ancient stone craftsmen.
    He discusses the puzzle of how these craftsmen cut the 43 giant granite beams, weighing between 45 and 70 tons each, and used in the King’s Chamber.
    Although the Egyptians are not given credit for the simple wheel, 2 the machine marks they left on the granite found at Giza suggests a much higher degree of technical accomplishment. Petrie’s conclusion regarding their mechanical abilities shows a proficiency with the straight saw, circular saw, tube-drill and, surprisingly, even the lathe.
    He goes on to mention the two diorite bowls in Petrie’s collection which Petrie believed must have been turned on a lathe, because they could ‘not be produced by any grinding or rubbing process’. Petrie had detected a roughness in one of the bowls, and found that it was where two radii intersected, as if a machinist had failed to ‘centre’ the bowl correctly on the lathe, and had re-centred it more precisely.
    Examining blocks that had been hollowed out—with some kind of drill—in the Valley Temple, Dunn states that the drill marks left in the hole show that it was cutting into the rock at a rate of a tenth of an inch for every revolution of the drill, and points out that such a phenomenal rate could not be achieved by hand. (Petrie thought it could, but only by applying a pressure of more than a ton on the drill—it is not clear how this tould be achieved.) An Illinois firm that specialises in drilling granite told Dunn that their drills—spinning at the rate of 900 revs per minute—only cut into it at one ten thousandth of an inch per revolution, so in theory the ancient Egyptians must have been using a drill that worked 500 times faster than a modern drill.
    Another aspect of the problem began to provide Dunn with a glimmer of a solution. A hole drilled into a rock that was a mixture of quartz and feldspar showed that the ‘drill’ had cut faster through the quartz than the feldspar, although quartz is harder than feldspar. The solution that he suggests sounds almost beyond belief. He points out that modern ultrasonic machining uses a tool that depends on vibration . A jackhammer used by navvies employs the same principle—a hammer that goes up and down at a tremendous speed, raining hundreds of blows per minute on the surface that has to be broken. So does a pneumatic drill. An ultrasonic tool bit vibrates thousands of times faster.
    Quartz crystals are used in the production of ultrasonic sound, and conversely, respond to ultrasonic vibration. This would explain why the ‘bit’ cut faster through the quartz than the