I firmly believe that so far as I have gone it is correct--and it is possible, therefore, with the start that I have made, for others to continue the work, and add the eleven pyramids to the plan in their correct geometrical position. By continuing the system of evolution by which I defined the position of Cephren, and the little pyramid to the south-east of Cheops, after I had obtained Cheops and Mycerinus, may be rebuilt, at one and the same time, a skeleton of the trigonometrical tables of a forgotten civilization, and the plan of those pyramids which are its only link with the present age. § 13. THE SIZE AND SHAPE OF THE PYRAMIDS INDICATED BY THE PLAN. I pursued my investigations into the slopes and altitudes of the pyramids without reference to the plan, after once deciding their exact bases. Now it will be interesting to note some of the ways in which the plan hints at the shape and size of these pyramids, and corroborates my work. The dimensions of _Cheops_ are indicated on the plan by the lines EA to YA, measuring 840 and 288 R.B. cubits respectively, being the half periphery of its horizontal section at the level of Cephren's base, and its own altitude from its own base. (_See Fig_. 5.) The line EA, in fact, represents in R.B. cubits the half periphery of the bases of either Cheops or Cephren measured at the level which I have set forth as the _plan level_, viz., base of Cephren. The ratio of Cephren's base to Cephren's altitude is indicated on the plan by the ratios of the lines BC to EB, or FO to OR, viz., 32 to 21. (_See Fig._ 4.) The altitude of Mycerinus above Cephren's base appears on plan in the line EF, measuring 136 R.B. cubits. The line EO on plan measures 888 cubits, which would be the length of a line stretched from the apex of Cheops to the point E, at the level of Cheops' base. This merits consideration:--the lines EA and AY are connected on plan at the centre of Cheops, and the lines EO and EA are connected on plan at the point E. Now the lines EO, EA and AY are sides of a "primary triangle," whose ratio is 37, 35, 12, and whose measure in cubits is 888, 840, and 288; and if we suppose the line EA to be stretched horizontally beneath the pyramids at the level of the base of Cheops from E to A on plan, and the line AY to be a plumb line hanging from the apex of Cheops to the level of his base, then will the line EO just stretch from the point E to the apex of Cheops, and the three lines will connect the two main pyramids by a vertical triangle of which EA, AY and EO form the base, perpendicular, and hypotenuse. Or, to explain it in another manner: let the line EA be a _cord_ stretching horizontally from A at the centre of the base of Cheops to the point E, both ends being at the same level; let the line AY be a _rod_, lift it on the end A till it stands erect, then is the end Y the apex of Cheops. Now, the line EO would just stretch from the top of the rod AY to the point E first described.