But in two or three of them, broken into by Colonel H. Vyse, a most interesting discovery was made about thirty years ago. The surfaces of some of the stones were found painted over in red ochre or paint, with rudish hieroglyphics--being, as first shown by Mr. Birch, quarry marks, written on the stones 4000 years ago, and hence, perhaps, forming the oldest preserved writing in the world. These accidental hieroglyphics usually marked only the number and position of the individual stones. Among them, however, Mr. Birch discovered two royal ovals, viz., Shufu (the Cheops of Herodotus) and Nu Shufu--"a brother" (writes Professor Symth) "of Shufu, also a king and a co-regent with him." Most, if not all, of the other pyramids are believed to have been erected by individual kings during their individual or separate reigns. If these hieroglyphics proved that _two_ kings were connected with the building of the Great Pyramid, that circumstance would perhaps account for its size and the duplicity and position of its sepulchral chambers.[241] The pyramid standing next the Great Pyramid, and nearly of equal size, is said by Herodotus to have been raised by the brother of Cheops. The other pyramids at Gizeh are usually regarded as later in date. But the exact era of the reign or reigns of their builders has not as yet been determined, in consequence of the break made in Egyptian chronology by the invasion of the Shepherd Kings. In their mode of building, the various pyramids of Gizeh, etc., are all similar, and the Great Pyramid does not specially differ from the others. "There is nothing" (observes Professor Smyth) "in the stone-upon-stone composition of the Great Pyramid which speaks of the mere building problem to be solved there, as being of a different character, or requiring inventions by man of absolutely higher order than elsewhere." But the Great Pyramid has been imagined to contain some hidden symbols and meanings. For "it is the manner of the Pyramid" (according to Professor Smyth) "not to wear its most vital truths in prominent outside positions." ALLEGED METROLOGICAL OBJECT OF THE GREAT PYRAMID.