rows on either side, they planted 122 columns with lotus-bud capitals.  The roof of the great nave rose to a height of 75 feet above the level of the ground, and the pylon stood some fifty feet higher still.  During a whole century, three kings laboured to perfect this hypostyle hall.  Rameses I. conceived the idea; Seti I. finished the bulk of the work, and Rameses II. wrought nearly the whole of the decoration.  The Pharaohs of the next following dynasties vied with each other for such blank spaces as might be found, wherein to engrave their names upon the columns, and so to share the glory of the three founders; but farther they did not venture.  Left thus, however, the monument was still incomplete.  It still needed one last pylon and a colonnaded court.  Nearly three centuries elapsed before the task was again taken in hand.  At last the Bubastite kings decided to begin the colonnades, but their work was as feeble as their, resources were limited.  Taharkah, the Ethiopian, imagined for a moment that he was capable of rivalling the great Theban Pharaohs, and planned a hypostyle hall even larger than the first; but he made a false start.  The columns of the great nave, which were all that he had time to erect, were placed too wide apart to admit of being roofed over; so they never supported anything, but remained as memorials of his failure.  Finally, the Ptolemies, faithful to the traditions of the native monarchy, threw themselves into the work; but their labours were interrupted by revolts at Thebes, and the earthquake of the year 27 B.C. destroyed part of the temple, so that the pylon remained for ever unfinished.  The history of Karnak is identical with that of all the great Egyptian temples.  When closely studied, the reason why they are for the most part so irregular becomes evident.  The general plan is practically the same, and the progress of the building was carried forward in the same way; but the architects could not always foresee the future importance of their work, and the site was not always favourable to the development of the building.  At Luxor (fig. 86), the progress went on methodically enough under Amenhotep III. and Seti I., but when Rameses II. desired to add to the work of his predecessors, a bend in the river compelled him to turn eastwards.  His pylon is not parallel to that of Amenhotep III., and his colonnades make a distinct angle with the general axis of the earlier work.  At Philae (fig. 87) the deviation is still greater.  Not only is the larger pylon out of alignment with the smaller, but the two colonnades are not parallel with each other.  Neither are they attached to the pylon with a due regard to symmetry.  This arises neither from negligence nor wilfulness, as is popularly supposed.  The first plan was as regular as the most symmetrically-minded designer could wish; but it became necessary to adapt it to the requirements of the site, and the architects were thenceforth chiefly concerned to make the best of the irregularities to which they were condemned by the configuration of the ground.  Such difficulties were, in fact, a frequent source of inspiration; and Philae shows with what skill the Egyptians extracted every element of beauty and picturesqueness from enforced disorder.