The author of Bædeker's _Guide_ has not been content with believing, like Perring, Lepsius, and Mariette, that the pyramid grew by the application of successive envelopes of stone round the central mass, either in horizontal courses or in courses sloping towards the axis of the building. He has brought forward an elaborate theory of construction, which, though very ingenious, encounters several grave objections. We shall point out those objections while we endeavour to explain the system itself by the help of special illustrations drawn for us by the author of the _Guide_ in question.[189] [189] _Ægypten_, First part, 1878, p. 341. [Illustration: FIG. 130.--The three great pyramids; from the south.] When Cheops first began to think about building his tomb, he could not have counted upon giving it the colossal dimensions which it presents even in its actual injured condition. The area of the great pyramid is more than double that of Saint Peter's at Rome. If we deduct from its total volume the core of rock which it incloses[190] and the openings which it contains, the masonry in its primitive integrity must have amounted to a total of 3,479,600 cubic yards. Even now, when so much of its substances has been detached and carried away, there still remains the enormous mass of 3,246,600 cubic yards. Supposing that, two or three years after the commencement of a work upon this colossal scale, death had carried off its projector, can we believe that any successor, even a son who was sincerely devoted to the memory of his father, would have burthened himself with the continuation and completion of such an enterprise? The new sovereign would have enough to do in commencing and carrying on the erection of his own tomb, and, moreover, would be irresistibly tempted to make use, for its construction, of the accumulated material and collected labour of his predecessor. [190] It has been suggested by Mr. Cope Whitehouse that the nucleus of rock under the great pyramids was originally much more important than is commonly supposed. During his expedition in March, 1882, he ascertained that a profile from the Mokattam across the Nile valley into the western desert would present the contours shown in the annexed woodcut. He concludes that a large part of the material of those pyramids was obtained upon their sites, and quarried above the level at which the stones were finally placed. He cites HERODOTUS (ii. 125) as conveying in an imperfect form the tradition that the pyramids were "constructed from above."