IgIQ.] Seistan and the Helmand. 5 
Helmand system.' Except in times of exceptional flood the 
Shelagh is a deep stream-bed, dry except for scattered pools of 
water so saline that tamarisk twigs at the edge are coated half an 
inch thick with salt ; but the water in flood-times, at the very site 
of these pools, becomes readily drinkable and the river is a raging 
torrent. Similarly the Gaud-i-Zirreh is at most seasons a wide 
plain covered with a thick deposit of salt and containing pools and 
swamps of saline water ; but it may become a real lake for the time 
being, with water of comparatively but not actually low salinity. 
The climate of Seistan, though regular from year to year, 
is one of considerable extremes and with only two seasons, summer 
and winter. In December and January the temperature usually 
falls below freezing point at night, while in summer it frequently 
rises to T15°F. in the shade by day, with a maximum of about 117°. 
It is, however, very exceptional for the larger bodies of water to 
freeze completely, while the summer heat is tempered by an 
almost unceasing wind. Wind,” indeed, seems to be the most con- 
stant feature of the climate, and its direction seldom changes. 
The direction is about N.N.W. For weeks on end in summer time 
it does not stop, and even in winter windy days are commoner 
than calm ones, and the wind is as arule practically N.N.W. Such 
rain as falls, falls mainly between the end of December and that of 
April, in which thunderstorms accompanied by hail and causing 
sudden floods sometimes occur; but the real flood-season takes 
place when the snows begin to melt in Afghanistan between March 
and May. 
Different Types of Aquatic Environment in Seistan. 
A summary description of the Helmand-system and the cli- 
mate of Seistan has been necessary to explain the very existence of 
the Hamun-i-Helmand as a lake, and of an aquatic fauna in the 
country. A detailed account® of the system would be impossible 
| In high floods a certain amount of water runs from the Helmand direct into 
the southern part of the Hamun system through a channel probably of artificial 
origin, and in exceptionally high floods some may flow direct into the Gaud-i- 
Zirreh, but this is not the normal course. 
2 ** At the end of May, or middle of June, the celebrated bad-i-sad-o-bist rug 
(120 days’ wind) sets in and blows with but little cessation till the middle or end of 
September. It blows unceasingly for four or five days at a time, usually attaining 
its maximum daily velocity between midnight and 5 a.M and again between 8 A.M. 
and5p.M. It moderatesa littlein the early morning andevening. After four or five 
days it drops a little for a day or two, only to recommence with renewed violence. 
It blows with appalling violence, reaching the maximum velocity. as recorded by 
the Mission anemometers, of 72 miles per hour. It blows always from one direc- 
tion, viz. a little west of north, i.e. between 3163° and 3332°.’’ (From an official 
document). 
8 The most complete account of the topography of Seistan yet published is 
to be found in Tate’s Sefstan. A Memoir on the History, Topography, Ruins 
and People of the Country, Parts I-IV (Calcutta, 1910 and 1912). See also 
McMahon “ The Southern Borderland of Afghanistan,’’ Geog. Fourn. 1X, pp. 393- 
415 (1897), zd., ‘‘Recent Survey and Exploration in Seistan,’’ Vol. XXVIII, 
PP: 3337340 (1906), and Rawlinson ‘‘ Notes on Seistan,”’ Fourn. Roy. Geog. Soc. 
II, pp. 272-294 (1873). 
