At the end of their desert journey the travellers overland, before the Canal was made, came to the city of Cairo. We see it here with its citadel in the foreground. Notice within the citadel the great Mohammedan mosque with its towering minarets. Cairo is now occupied by the British, and there is freedom of religion for all races, as in every part of the British Empire. Close to Cairo are famous monuments, the Pyramids and the Sphinx, built some six thousand years ago. We see the Pyramids first in the distance as we drive from Cairo along this road. The trees which you see are watered daily, for rain is very rare in Egypt. Here we have arrived at the Pyramids, which are just on the desert edge, because the land watered by the Nile is too valuable for purposes of cultivation to permit of their being placed on fertile ground. The Pyramids and the Sphinx have hardly changed in this intensely dry climate through the space of 6,000 years, although the Sphinx has been partly buried in the sand. In order that you may appreciate the size of the Pyramids let us show a party of tourists climbing the great Pyramid, and note the huge blocks of stone of which it is built. [Sidenote: 39. The Nile Valley in Flood.] And now let us ask the question for which we are making this excursion from the Suez Canal into Egypt. How comes it that here, in the rainless desert, there is fresh water to make possible the cutting of the Suez Canal? It is because the Nile, the river of Egypt, comes from the South beyond the desert. There every summer the rains fall in Abyssinia, and the Egyptian Nile, far away to the north, rises in flood. Here is a view, taken from the edge of the desert at the brink of the valley, in the time of the annual flood. When the water subsides the crops are sown, and presently the harvest is reaped without so much as a shower of rain to aid the growth. [Sidenote: 40. The Assouan Dam.] [Sidenote: 41. Opening of the Assouan Dam.]