A very short way, as it looks on the map of the Western Hemisphere, to the east of that Levant shore, you may see the two rivers Euphrates and Tigris, rising very near together only a little south of the Black Sea, yet not finding their way out into the sea till they have gone a very long way south. Then, after coming together, they go out in each other's company into the Persian Gulf. A great part of that space between the two rivers is called Mesopotamia, {3} and is the country where our armies had hard fighting in the Great War. Mesopotamia is from Greek μέσος, meaning the middle, and πόταμος, a river, and means the land in the middle of, or between, the two rivers. Mediterranean, the name of the big sea, is from Latin _medius_, meaning, again, the middle, and _terra_, the earth; that is to say, the sea in the middle of the land. It is almost entirely shut in by the land, its only way out being by the narrow Straits of Gibraltar at the western end. [Sidenote: The great rivers] So there you see those two rivers, Euphrates and Tigris, running south and making the land in the neighbourhood of their course very rich and fertile, producing splendid crops and vegetation of all kinds. And now, if you will carry your eye just a little to the west and south of these, across Arabia and the Red Sea, you will see another great river, only this time it is a river running, not from the north to the south, but from the south to the north. It is the Nile, the river of Egypt. It goes out into the Mediterranean past a city called Alexandria. At its mouth it spreads out into a number of channels, making an area intersected by water channels. This area has something of the shape of the letter in the Greek alphabet which corresponds to our "d" and is drawn thus Δ. That is roughly the shape of the space occupied by these many mouths of the Nile, and the region is therefore called the "Delta," which is the name of that letter of the Greek alphabet. I want you to take particular notice of these two great river-courses, those of the Nile and of the Euphrates with the Tigris. I say Euphrates "with Tigris," because the two are together the fertilisers and waterers of the country lying between and around {4} them. The Nile does his business of watering his own valley by himself. It is most important that you should give your attention to these two great water-courses, because it is along them that arose the two greatest empires, the two strongest and most formidable powers, of which the early history of the world has anything to tell us.