In a previous thread Clive suggested that it would be worthwhile to study the variations in core course heights on the Great Pyramid. Actually Petrie's already done that in an article in "Ancient Egypt" magazine in 1925 "The Great Pyramid Courses".

He begins by stating: "It had not previously been noted how the variations of the thickness of different courses of the Great Pyramid tended to group around certain lengths, and the enquiry hence arose, was this grouping due to different standards of measure used by the masons?"

As well as the fairly familiar graph of course heights that he published in his famous survey the article also contains a further set of graphs of more analysis. With typical thoroughness he describes his sampling process:

"As the courses vary much in precision they cannot be merely added all together; one course is the same to a tenth of an inch across the pyramid, another varies an inch or more. The only way to treat them is to give an equal area of the curve to each course; thus the uncertain courses will spread out shallow, and the exact courses will rise up high. To do this, each tenth of an inch of variation of a course was weighted inversely as the extent of variation."

His new graphs show the distribution of different layer heights with peaks highlighting layers of similar heights. Part of his conclusion reads:

"At the beginning of the curve it is clear that many courses were intended to be a cubit thick, 20.6 inches; there were also two courses of the double cubit of 41.2 inches. Between these we may see a digit measure used.. a peak at 50 digits, another at 40, the diagonal of the cubit. There may also be groups at 30, 32(?), 34, 36 and 38 digits. Thus many of the sizes of courses can be accounted for on the usual digit scale, just as our masons might work up irregular stones by trimming to the next inch of size" (the question mark after 32 is his not mine).

He goes on to explain his reasoning for these variations which I'll attempt to précis as it's rather lengthy.

Petrie agues that before work began on the actual pyramid, workers would have been splitting, extracting and storing stone for as much as ten years. These blocks would reflect the height of the strata they were cut from. The stones were then sorted for size and those nearest the "ideal" (ie one cubit) where dressed and finished. Stone further from the "ideal" was finished to a variety of sizes that required the least amount of work ie if a lot of stone was close to 30 inches then they would be reduced to that size. They were then delivered and used with the larger stones used first. Actually he says "naturally beginning with the largest" though I'm not quite sure why that is natural although I suppose that it's easier to lift a small stone higher than a heavy one.

(I'll would also add to his argument that stone of a particular size that was not used the first time around, because a particular layer was finished, could be stored until a supply of similarly sized stone had accumulated from the quarry sufficient for a new layer. Reducing the majority of the stones to a cubit height would have made this process more efficient.)

He goes on the state that each sequence of course heights (Goyon calls them tranches) reflects the next influx of stone from a new quarry or store. He identifies "apparently nineteen shifts of quarrying". Petrie was writing before the quarry for the limestone was identified at Giza so he was unaware that the stone seems to have been cut from one quarry quite close to the pyramid.

I'm not sure if that would have influenced his conclusions. Anyway he presents an argument that accounts for the varying course heights and the pattern that can clearly be seen.

The second part of the article is much more problematical but it's not just Petrie's work as he says "When in Egypt last year, Mr. J. Tarrell, of Alexandria, kindly showed me a paper on an interesting question which he had been studying, and wished that it should be bought forward and discussed".

Because Petrie has written the article it's not immediately clear which part is his and which come from Tarrell but at least the beginning of this is credited directly to Tarrell as written up by Petrie.

"... it is Mr. Tarrell's view that local measures were used, perhaps by groups of foreign captive workmen, and that such measures may have survived in use to late times. The group at 21.3 inches is the mediaeval Nilometer cubit. The group at 22.2 inches is the double foot of Syria, known from the XIIth dynasty at Byblos, and found in monuments down from Roman times. The group at 22.8 inches, which is one of the largest, is the popular Egyptian measures of the country, the dra'a beledy... ... there are strong suggestions of un-Egyptian measures, it is not unlikely that the large group at 26.3 inches is the double of the northern foot."

He goes on to describe a lot more foreign measures and even extends things to include modern measures tracing them back through the Germanic foot as far back as Silbury Hill.

I'm not convinced at all by the notion of foreign workers importing their standard measures. Surely it would create havoc to work with a whole set of different measurement systems and I don't think there's any evidence now from recent work on the workman's tombs etc that foreign workers were involved at all. Indeed modern opinion dismisses the whole idea of slave labour at the pyramids. The article is from 1925 though and opinions change and new evidence comes to light and this particular idea doesn't, as far as I know, appear anywhere else and I don't think it stands up to scrutiny now.

The first part of the article and the analysis of the layer heights is still valid though.

Jon

www.egyptarchive.co.uk