ARGHANDAB, an Afghan river rising in the Hazara coun try north-west of Ghazni and flowing south-westward into the Hel mand, tom. below Girishk. Its upper course is said to be shallow and almost dry in summer, but it is very rapid and difficult to ford at other times. Irrigation results in a good population on its lower course, but here the water is said to be slightly brackish. It is 2 5om. long, and its chief confluent, the Tarnak, Zoom. long, dis putes with it the right to the ancient name Arachotus. The ruins at Ulan Robat, the supposed city of Arachosia, are in the Tarnak basin to the east of which lies Lake Ab-Istadah, the supposed Lake Arachotus. The Tarnak valley is used by the high road from Kabul to Kandahar, another reason for thinking it the Arachotus.