Since this ceiling could not remain in mid-air without support, four columns, or rather four forked trunks of trees, similar to those which maintained the primitive house, were supposed to uphold it. But it was doubtless feared lest some tempest should overturn them, for they were superseded by four lofty peaks, rising at the four cardinal points, and connected by a continuous chain of mountains. The Egyptians knew little of the northern peak: the Mediterranean, the "Very Green," interposed between it and Egypt, and prevented their coming near enough to see it. The southern peak was named Apit the Horn of the Earth; that on the east was called Bakhu, the Mountain of Birth; and the western peak was known as Manu, sometimes as Onkhit, the Region of Life. [Illustration: 023.jpg FOOTNOTES WITH GRAPHICS] Bakhu was not a fictitious mountain, but the highest of those distant summits seen from the Nile in looking towards the red Sea. In the same way, Manu answered to some hill of the Libyan desert, whose summit closed the horizon. When it was discovered that neither Bakhu nor Manu were the limits of the world, the notion of upholding the celestial roof was not on that account given up. It was only necessary to withdraw the pillars from sight, and imagine fabulous peaks, invested with familiar names. These were not supposed to form the actual boundary of the universe; a great river--analogous to the Ocean-stream of the Greeks--lay between them and its utmost limits. This river circulated upon a kind of ledge projecting along the sides of the box a little below the continuous mountain chain upon which the starry heavens were sustained. On the north of the ellipse, the river was bordered by a steep and abrupt bank, which took its rise at the peak of Manu on the west, and soon rose high enough to form a screen between the river and the earth. The narrow valley which it hid from view was known as Da'it from remotest times. Eternal night enfolded that valley in thick darkness, and filled it with dense air such as no living thing could breathe. Towards the east the steep bank rapidly declined, and ceased altogether a little beyond Bakhu, while the river flowed on between low and almost level shores from east to south, and then from south to west. The sun was a disc of fire placed upon a boat. At the same equable rate, the river carried it round the ramparts of the world. Erom evening until morning it disappeared within the gorges of Dait; its light did not then reach us, and it was night. From morning until evening its rays, being no longer intercepted by any obstacle, were freely shed abroad from one end of the box to the other, and it was day. The Nile branched off from the celestial river at its southern bend;[*] hence the south was the chief cardinal point to the Egyptians, and by that they oriented themselves, placing sunrise to their left, and sunset to their right.