Chris
Saqqara ostracon.
The bent arm, from my metrological studies, indicates the common cubit, the straight line beneath is not a palm sign and the curved-like markings are not fingers. The tomb grids of Giza are laid out according to a unit which is the equivalent of .363 inches and so too are the five instructions on the Saqqara ostracon only in different combinations, combinations however which are easy to relate to.
The curve of the Saqqara ostracon has nothing to do with a full circle for it is clearly flattened at the top. The curve is in two parts. Both parts are however related to each other through simple geometry. There are no x,y co-ordinates at Saqqara and it is not the first instance of such.
This business of common cubit, royal cubit hinges on a correct interpretation of the early bent arm sign.
On the best evidence we have the early Egyptians were typically short 5ft 5" - 5ft 9" with an armspan of approximately 18 inches. There is evidence that both the Indus and Mesopotamian civilizations also had long and short cubits. The longer, the royal, as Herodotus correctly reported, is "three finger breadths" more which is supported by any human anatomy you care to consult. We only have three practical fingers to measure with. The cubit rods unearthed also show this multiple of three as I have repeatedly shown.
Cubits of 28 are a late addition and Ahmes the scribe, however celebrated he might be, had lost touch with the original metrology assigned to the measuring rod. Rods of 28 "more or less equal" divisions are in fact fakes, votive rods, gifts to the temple.
It all comes down to interpretation and yes, I do realize I am on unfamiliar ground but as Dave said ... there's a web article in the making ... soon.
Graham.