The Great Pyramid was built of limestone and granite throughout, the two kinds of rock being combined in a peculiar and significant manner. The stones were trued with the utmost precision, and the cement used was of such remarkable quality that it is now practically as hard as the stone itself. The limestone blocks were sawed with bronze saws, the teeth of which were diamonds or other jewels. The chips from the stones were piled against the north side of the plateau on which the structure stands, where they form an additional buttress to aid in supporting the weight of the structure. The entire Pyramid is an example of perfect orientation and actually squares the circle. This last is accomplished by dropping a vertical line from the apex of the Pyramid to its base line. If this vertical line be considered as the radius of an imaginary circle, the length of the circumference of such a circle will be found to equal the sum of the base lines of the four sides of the Pyramid.