Oct 13, 2014
Granite core (UC16036) or CORE 7 from Giza of 4th Dynasty date. (height. 11 cm. The Petrie Museum.) This spiral drill core was found inside Valley Temple. On the same site one of the doorway hinges hole has same drill markings…
Recently showcased on H2’s Ancient Impossible episode: ( http://goo.gl/SQCo2K ) But before Christopher Dunn has done an extensive analysis of this core… Both sources came to same conclusion. Some sort of very high/advanced machining had to be used to make such core/spiral markings… At very high speed which we can replicate even today!
Pics credits: C.Dunn, B. Foerster, Jon Bodsworth.