Indeed, we’ve been able to notice that the northern side of the ceiling contains a longitudinal joint situated at about ten centimeters from its junction with the eastern wall. It appears clearly, therefore, that there is a 12th rafter (numbering from west to east) which is largely hidden by the masonry of the eastern wall (fig. 2).
Trying to confirm our observation with the existing documentation, we have found that Vyse had noted the existence of the rafter n°12 by drawing clearly its joint in his cutting views. Perring also did it on its report of the inscriptions (fig. 1), but revealed it more clearly on another of its drawings.
From then on, the numbering of Petrie makes sense,..
> But then, we know that.
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