Hello Clive,

Thanks for the feedback.

As I expected, the measurements that produce your imaginary slope of 4139” are mostly incorrect.

The following sets of measurements are first yours and then Petrie’s.
Starting at the left side of your drawing:
1693 - 1691.6
35 - 35.1
1628 - 1627.9
681 - 679.7
172 - 173 to 173.4
1390 - 1389.5
4534 - 4537.2
1517 - 1519.8
524 - 525.6 to 527
668 - 668.2

Your slope is: vertical = 1693 – 668 = 1025; horizontal = 4534 – 524 = 4010; slope therefore 4138.9
By Petrie’s measurements: vertical = 1691.6” – 668.2 = 1023.4; horizontal = 4537.2” – 525.6 to 527 = 4010.2 to 4011.6; slope therefore 4138.7 to 4140”.

Now, as Jon_B has already rightly pointed out, these differences are insignificant if the measurements are only being used to produce a CAD drawing of the Pyramid and its interior.
But if they are for use in a theory about the significance of certain measurements, then one runs immediately into complications.
The imaginary (i.e. it is not the floor of a passage) slope you refer to is actually 4138.7 to 4140” long.
The length of the Descending Passage floor is 4148”.
Before you start on about Petrie’s measurement being 4140”, just consider the fact that if Petrie had had the Passage floor cleared of debris and other obstructions as thoroughly as the Edgar brothers and, later, Rutherford did, then he would undoubtedly have recorded the correct measurement of 4148”.

Now, is there any significance in these two measurements being, within 8”, the same length?
Well, with the entrance to the top of the face of the Great Step measurement we have a 90deg triangle: height 1023.4”, base 4010.9” ± 0.7”, hypotenuse 4139.4” ± 0.6”.
If the intent was for a slope measuring 4139.4”, then what was the other determining factor?
Was it the height @ 1023.4”, or was it the horizontal length @ 4010.9”?
And in both cases, how were the vertical and horizontal dimensions of the upper Descending Passage, Ascending Passage, Grand Gallery and Great Step each fitted in?
Or could it be that the determining factor was the gradient (seked) of the slope?
But, then, even this does not explain how the Descending Passage, etc., were fitted into the triangle.
Another possibility is that the vertical and horizontal locations of the entrance and the Great Step were the determining factors – but how did they get to be where they are?

The point is, one cannot say that there is significance in the Descending Passage floor length (regardless of the 8” difference) being almost the same as the imaginary entrance-to-Great-Step sloping line without explaining the vertical and horizontal measurements of and associated with the upper passages and the Great Step.
Do you have such an explanation, Clive?

MJ

We can't all be right, but we could all be wrong ...