Hello Jon,

This is something of an odd error, to say the least.

The horizontal measurements after Petrie are:
North side at base to foot of entrance = 525.63” to 526.96”
Foot of entrance to Descending Passage/Ascending Passage floor line intersection = 994.17” to 994.3”

Therefore North side at base to Descending Passage/Ascending Passage floor line intersection =
from 525.63” + 994.17” = 1519.8”
to 526.96” + 994.3” = 1521.26”
mean 1520.53” +/- 0.73”

From Descending Passage/Ascending Passage floor line intersection to Ascending Passage floor/Grand Gallery north wall intersection (a.k.a. horizontal length of Ascending Passage) = 1389.5”

From Ascending Passage floor/Grand Gallery north wall intersection to east apex of Queens' Chamber = 1626.5”

From east apex of Queens' Chamber to top of Chamber doorway at north-east corner = 102.6”

Therefore north side at base to top of Chamber doorway at north-east corner = mean 1520.53” +/- 0.73” + 1389.5” + 1626.5” - 102.6” = 4433.93” +/- 0.73”

If you take his accumulative measurement for the west apex of the Queens' Chamber as given @ 4533.8 and deduct from this his actual measurement for from west apex to north wall of Chamber @ 103”, then you are still left with an error, i.e. 28.7”.

Try as I may, I cannot see how Petrie arrived at 4402.1” for this total measurement.

MJ