Here is the product of an ancient civilization empowered with the knowledge that as long as the moon continued to orbit the Earth, the special relationship that existed between the two assured the Egyptians of vast amounts of energy. The source of the energy is the Earth itself, in the form of seismic energy. The ancient Egyptians saw tremendous value in this form of energy and expended a considerable amount of effort to tap into it. The benefits they received may have been twofold: energy to fuel their civilization, and the ability to stabilize the Earth's crust by drawing off seismic energy over a period of time rather than allowing it to build up to destructive levels.
The knowledge needed to evaluate certain of these ancient artifacts was not available until very recently. Even today there may be numerous articles that we will not understand until we further develop our own technology. We cannot fathom technology that is unknown to us, and we seldom consider things that seem impossible to us. Petrie, though knowledgeable in engineering and surveying, could not be expected to know anything about ultrasonic machining; hence his amazement at the machining abilities of the ancient Egyptians. Even if he had been aware of this technology, the intellectual climate of his time may have precluded his considering the possibility that these methods were known to the ancient Egyptians. Quite simply, the greatest barrier to our understanding may not necessarily be knowledge. It may be attitude.