Arab legends mentioned the use of the [P 003 / Great Pyramid] as an observatory and this was corroborated by the discovery of similar mention by the Neoplatonic philosopher, Proclus (fourth century), in his commentary on Plato's Timaeus. The 19th-century British astronomer, Richard Proctor, who stumbled upon this passage went on to describe how different astronomical functions were possible at various stages of the pyramid's construction, explaining the unique set of [I 046 / corridors] found within the Great Pyramid. This also gave a rationale for the Grand Gallery: an observation chamber before it was roofed over; ancient astronomers would use the top edges of the [G 006 / corbelled] [I 044 / walls] to accurately record the transits of the stars as they passed over. This would also explain the mysterious slots that mark the long floor ramp. They could be used to hold an observation platform from sliding along the polished floor.
