> Chris Dunn wrote:
> >Archae Solenhofen wrote:
> >>Chris Dunn wrote:
> >>Stocks conducted his experiments so that he could make some
> >>meaningful comparison to what the ancient Egyptians
> >>produced.... can you tell us what bearing a test using 80
> >>silicon carbide has to this discussion?
It provided me with an idea of the kind of results that can be obtained using an abrasive. It also provided me with information on the efficiency of a harder substance than quartz, as described by Gorelick and Gwinneth, and how it held up under pressure. It also gave me an idea of how difficult it is to remove the dust that accumulates in the slot so as to introduce fresh grit if one does not have compressed air to blow it out. It also provided me with information regarding how a copper wedge performs when trying to remove the core.
It was a very useful experiment for me.
> >To my mind the question is quite simple. There is the original
> >Egyptian core and then there is Stocks' core and my core. The
> >original should be completely analyzed and described, then
> >drilling attempt should be compared with the original in the
> >same way. If Stocks has a core that is the same as the
> >Egyptian, then he should show its details and describe the
> He did... tapered core, rough lapidary polish, and horizontal
> striations produced by the bow-powered cutting.
I have his publications and there is nothing shown with which one could apply the same scrutiny It would be nice if he would show the results in greater detail.
> >As silicon carbide is harder than quartz (9 mohs SiC to 7 mohs
> >quartz) and Gorelick and Gwinneth testified that this hardness
> >produced deeper grooves, I don't see any problem in using
> >material instead of quartz sand.
> I did not realize "quartz sand" was just restricted to 80 mesh
> abrasive. Again, why are you arbitrarily choosing 80 mesh as
> the only grain size in your experiment? I also still do not
> understand the logic of using something both synthetic and
> harder than a natural compound like emery as the abrasive.
> >If we take Gorelick's and
> >Gwinneth's observations and if hardness has anything to do
> >cutting granite, it would seem that the process would go
> >and yield better results.
> Ya, only in the case of the same lapping characteristics
> compared between two abrasives of different hardness. Why would
> the ancient Egyptians only use 80 mesh abrasive quartz abrasive
> to cut granite?
They didn't use quartz sand to cut granite.
> Striation depth would be dependent on a number of factors
> including grain size, mechanical and other physical properties
> of the grains in the abrasive, ideal lapping pressure (which
> varies from abrasive to abrasive due to variables like
> compressive fracture strength which are not the same for quartz
> and silicon carbide), the mineral composition of the granite
> used, etc. How did Gorelick and Gwinneth take these variables
> into consideration when asserting, as you seem to be
> insinuating, that hardness is the only factor dictating
> striation depth?
> >However, if you are saying that
> >quartz sand of a larger grain size is more appropriate, let's
> >see the results.
> Lets see your results with quartz sand first.... not 80 mesh
> silicon carbide. Keep you experiment to something that can be
> related to the material and technology available to the 4th
> dynasty ancient Egyptians as well as realistic and common sense
> lapidary techniques.
Let's see the results of Stocks's drilling experiment. Photographs of the same quality and detail as Gorelick and Gwinneth.
> >Perhaps the quartz holds up better than the
> >harder material, which has to be refreshed quite frequently as
> >it doesn't take long to turn into dust.
> This is the case for all good lapidary abrasives, the grains
> need to break so that new sharp edges are produced. Otherwise
> one gets round grains that act like ball bearings reducing the
> effectiveness of the abrasive.
Are you claiming that quartz sand wears better than SiC?
> >>>Stocks makes this claim, but offers no photographic
> >>>proof to support it.
> >>I did not realize Stocks' observation skills and expert
> >>were in doubt here.
I do not doubt his observation skills or expert opinion, I would just like for him to fill in some gaps. It would have been helpful for him to describe with more detail what he is attempting to replicate. For instance, Petrie provides a detailed study of core #7 in the Petrie Museum. Close up photographs of ancient drilled holes with their deep striations would have also been helpful. This information was lacking. Then clear and visible photographs of the results of his work, with an analysis of the grooves with the same thoroughness that Petrie provides. This information is absolutely necessary to substantiate the claim.
> >Don't you want to see more scientific evidence from Stocks?
> Sure would, but it is not required for his observation of
> "similar". I have no reason to not except his observations as
You and many other people, no doubt. But a reasonable request for a more thorough analysis should not be hard to accommodate.
> >Would you not demand it from me if I made the same claims that
> >he has?
> Well, I have for some of your claims..... and for good reason.
And you did have good reason, I agree. Just as I have good reason to ask for a more detailed examination of Stocks's claims.
> >Perhaps a photograph with the same clarity and detail
> >that Jon Bodsworth provides?
> Now that you bring it up, I seem to remember asking you many
> years ago to identify exactly which of the clearly visible
> grooves in that photo of Jon's was the ones that you measure as
> spiraling a number of turns and I did not get what I would
> consider as a very useful answer to such.
> Here it is again.....
> (height. 11 cm. The Petrie Museum, Photograph by Jon Bodsworth
> Can you please provide its exact location on the photo by
> marking the clearly visible grooves you measured from where
> they begin in the photo, and each successive turn, to where
> they end in the photo so we can understand exactly what it was
> you were measuring.
As you know, I verified that it was spiral groove, using a cotton thread to wrap around the groove. I will provide you, though, with Petrie's meticulous measurements, which are given below in inches.
________________Quarter Turns________|First Repeat
Flinders Petrie, Sir William M. “On the Mechanical Methods of the Ancient Egyptians.”Journal of the Anthropological Institute (1884), p.104
> Archae Solenhofen (email@example.com)