The basin of Sistan is unique. Its streams, at least during floods, focus in a fresh-water lake, exceedingly flat-bottomed and shallow, and without an outlet to the sea. About this circles a broad band of reedy swamp, the home of innumerable wild fowl and of the strange Sayids who gain a livelihood by netting them. Next comes a band of smooth, rich plain, splendidly fertile and capable of supporting a dense population, but hounded suddenly and even encroached upon by the grim belt of the surrounding desert. Wastes of blown sand, dry pools of glistening salt, and vast expanses of dark, lifeless gravel form the desert which comprises half the area of the basin and completely cuts off the inner, more hospitable regions from the surrounding mountains and the rest of the world. In its sterile wastes all the streams except the Helmund wither to nothing and are wasted, except when the floods of spring carry them clear to the central lake. Outside of these four belts—the lake, the swamp, the plain, and the desert—the basin is everywhere bounded by mountains. On the west and south, where they lie close to the lowest depression, the mountains are low and arid. The streams which rise in them are niere wet-weather torrents, which lose themselves in the piedmont gravel a few miles from their source. To the east, however, and even more to the north, the mountains are among the grandest in the world. From the northeast angle of the basin, near Kabul, the continuation of the Hindu Kush Mountains stretches westward for a distance of 400 miles to the Afghan depression. Of this slightly explored region, larger than New England, we know almost nothing, except that magnificent mountains, from I0,000 to 17,000 feet in height, pour their melted snows into the tremendous gorges of rushing rivers, the Harud, the Farah, the Khash, and the many branches of the Helmund. Where these streams reach the lower mountains, their valleys widen and are filled with fields, orchards, and prosperous villages, and a strip of green abundance intervenes between the sterile mountains and the sterile plain. (See plate 6, opposite p. 288.)
THE HELMUND RIVER.
The main features of all the larger rivers of the Sistan basin may be illustrated by a single example. The Helmund of the Afghans, the Etymander of the ancients, is the only large river between the Tigris and the Indus. Rising among great mountain peaks which tower to heights of over 15,000 feet, the Helmund flows through the land of the Hazara Mongols (Holdich, a, p. 42), "a wild mountainous country of which no European has seen much more than the outside edge. It is a high, bleak, and intensely inhospitable country, where the snow lies for most months of the year, where little or no fuel is to be found, and cultivation is confined to the narrow banks of the Helmund and its tributaries." Farther downstream, near the edge of the mountains, Zamindawar, northwest of Kandahar is a beautiful country, stretching up in picturesque valleys and sweeping curves from the Helmund, and filled with a swarming population of well-to-do cultivators " (p. 43). From Zamindawar the river flows southward, and not far below Girishk enters the desert, through which it flows for 300 miles to Sistan, first southward, then westward, and lastly northward. On the left lie the deserts of Registan and northern Baluchistan, which McMahon (a, pp. 13, 14, 16 ; b, p. ego) and Holdich (a, p. 104-105) describe