Being aware of angles and measuring those angles is not the same as understanding the underlying reason. Petrie was a great surveyor, but his mathematical reasoning is far from rigorous in his publications, and has raised many eyebrows.

In order to understand Petrie you need to start off by reading his 'Inductive Metrology' which he wrote when he was 23 years old. I went back even further to a little known publication on the pyramids, which may have been written when he was teenager. A beautifully bound book, but one should not judge a book by its cover.

The 63 cubits arises from the level of the bend at 90 royal cubits and his angle of 10/7. It could not be measured. Petrie was, of course, home educated, but this shows that he could work out '63 cubits' from school boy geometry based on his determination of the side-length as 360 royal cubits.

Incidentally, I decided to look at Petrie's unpublished notebook on the Great Pyramid. By contrast, Professor Smyth's notebooks are superb.

An inconsistency in Petrie's table of results on the Great Pyramid can be dismissed as a error as it fails a geometric test, but his notes pass the test, so it was merely an typographical error. Unfortunately, John Romer used the offending measurement to support his sliding grid theory in his book on the Great Pyramid, as published by Cambridge University Press. This is an aside, mentioned here so you don't fall into the trap of thinking Petrie's work was infallible.

It is very easy to misinterpret Petrie unless one fully understands his methodology, which is only possible by reading his early works on pyramids. I recently read that scholars distance themselves from some of his metrological claims related to Stonehenge, which were made after over forty years of surveying ancient monuments. Petrie saw units of length that no-one else accepts, as if the influence of the Pyramid Inch, of which he was a one-time disciple, had an enduring effect on his desire to discover something truly remarkable.

You have to differentiate between 'results' and 'measurements'. The former have actually gone through the mangle of calculation and supposition, generally worded well enough to convince his readers, but cleverly enough to avoid the charge of having stated a matter as a fact when it was merely a hypothesis.

Full details on Alpha Draconis and its proximity to the pole are given in my latest website.

Mark





Edited 2 time(s). Last edit at 01/09/2015 06:43PM by Hermione.