An island was therefore formed by the sea and by both streams of the river, which is called Delta from the resemblance of its shape to the letter (Δ) of that name. The spot at the vertex of the triangle has the same appellation, because it is the beginning of the above-mentioned triangular figure. The village, also, situated upon it is called Delta. These then are two mouths of the Nile, one of which is called the Pelusiac, the other the Canobic and Heracleiotic mouth. Between these are five other outlets, some of which are considerable, but the greater part are of inferior importance. For many others branch off from the principal streams, and are distributed over the whole of the island of the Delta, and form many streams and islands; so that the whole Delta is accessible to boats, one canal succeeding another, and navigated with so much ease, that some persons make use of rafts[801] floated on earthen pots, to transport them from place to place. The whole island is about 3000 stadia in circumference, and is called, as also the lower country, with the land on the opposite sides of the streams, the Delta. But at the time of the rising of the Nile, the whole country is covered, and resembles a sea, except the inhabited spots, which are situated upon natural hills or mounds; and considerable cities and villages appear like islands in the distant prospect. The water, after having continued on the ground more than forty days in summer, then subsides by degrees, in the same manner as it rose. In sixty days the plain is entirely exposed to view, and dries up. The sooner the land is dry, so much the sooner the ploughing and sowing are accomplished, and it dries earlier in those parts where the heat is greater. The country above the Delta is irrigated in the same manner, except that the river flows in a straight line to the distance of about 4000 stadia in one channel, unless where some island intervenes, the most considerable of which comprises the Heracleiotic Nome; or, where it is diverted by a canal into a large lake, or a tract of country which it is capable of irrigating, as the lake Mœris and the Arsinoïte Nome, or where the canals discharge themselves into the Mareotis. [CAS. 789] In short, Egypt, from the mountains of Ethiopia to the vertex of the Delta, is merely a river tract on each side of the Nile, and rarely if anywhere comprehends in one continued line a habitable territory of 300 stadia in breadth. It resembles, except the frequent diversions of its course, a bandage rolled out.[802]