2006 and The Secret of the Great Pyramid, co-written in 2008 with Egyptologist Bob Brier. In Houdin's method, each ramp inside the pyramid ended at an open space, a notch temporarily left open in the edge of the construction. This 10-square-meter clear space housed a crane that lifted and rotated each 2.5-ton block, to ready it for eight men to drag up the next internal ramp. There is a notch of sorts in one of the right places, and in 2008 Houdin's co-author Bob Brier, with a National Geographic film crew, entered a previously unremarked chamber that could be the start of one of these internal ramps. In 1986 a member of the French team (see below) saw a desert fox at this notch, rather as if it had ascended internally. Houdin's thesis remains unproven and in 2007, Egyptologist David Jeffreys from the University College London described the internal spiral hypothesis as "far-fetched and horribly complicated", while Oxford University's John Baines, declared he was "suspicious of any theory that seeks to explain only how the Great Pyramid was built". Houdin has another hypothesis developed from his architectural model, one that could finally explain the internal "Grand Gallery" chamber that otherwise appears to have little purpose. He believes the gallery acted as a trolley chute/guide for counterbalance weights. It enabled the raising of the five 60-ton granite beams that roof the King's Chamber. Houdin and Brier and the Dassault team are already credited with proving for the first time that cracks in beams appeared during construction, were examined and tested at the time and declared relatively harmless. See also Ancient Egyptian technology List of megalithic sites Seven wonders of the world Herodotus Machine References External links How to Build a Pyramid, Archaeology Magazine, May/June 2007 Engineering the Pyramids - Materials Science and Engineering @ Drexel University Rope pull hypothesis - alternative hypothesis by Heribert Illig and Franz Löhner Collection of alternative construction essays Did the Great Pyramid Have an Elevator? The Structural Engineer, April 2009 The main problems / drawbacks of all ramp systems 3D Unveils Great Pyramid's Mystery - illustrates hypothesis of Houdin and Brier. Did the Egyptians create a canal and a port to bring stone to the Great Pyramid? A Device for Lifting Pyramid Stones Construction technique History of construction Pyramid construction techniques Pyramid construction techniques Hypotheses