The Zerreh or Sea of Seistan--called sometimes the Hamun, or “expanse”--is situated in the Seistan Desert on the Great Iranic plateau, and consequently at an elevation of (probably) 3000 feet. It is formed by the accumulation of the waters brought down by the Helmend, the Haroot-rud, the river of Khash, the Furrah-rud and other streams, which flow from the mountains of Afghanistan, with converging courses to the south-west. It is an extensive basin, composed of two arms, an eastern and a western. The western arm, which is the larger of the two, has its greatest length from N.N.E. to S.S.W., and extends in this direction about ninety miles. Its greatest width is about twenty-five miles. The eastern arm is rather more than forty miles long, and from ten to twenty broad. It is shaped much like a fish’s tail. The two arms are connected by a strait seven or eight miles in width, which joins them near their northern extremities. The water of the lake, though not salt, is black and has a bad taste. Fish support life in it with difficulty, and never grow to any great size. The lake is shallow, not much exceeding a depth of three or four feet. It contracts greatly in the summer, at which time the strait connecting the two arms is often absolutely dry. The edges of the lake are clothed with tamarisk and other trees; and where the rivers enter it, sometimes by several branches, the soil is rich and cultivation productive; but elsewhere the sand of the desert creeps up almost to the margin of the water, clothed only with some sickly grass and a few scattered shrubs. The Birket-el-Keroun, or Lake Moaris of the classical writers, is a natural basin--not, as Herodotus imagined, an artificial one--situated on the western side of the Nile valley, in a curious depression which nature has made among the Libyan hills. This depression--the modern district of the Faioom--is a circular plain, which sinks gradually towards the north-west, descending till it is more than 100 feet below the surface of the Nile at low water. The Northern and northwestern portion of the depression is occupied by the lake, a sheet of brackish water shaped like a horn (whence the modern name) measuring about thirty-five or thirty-six miles from end to end, and attaining in the middle a width of between five and six miles. The area of the lake is estimated roughly at 150 square miles, its circumference at about ninety miles. It has a depth varying from twelve to twenty-four feet. Though the water is somewhat brackish, yet the Birket contains several species of fresh-water fish; and in ancient times its fisheries are said to have been exceedingly productive.