~The Ghagar and the Sarusti.~--The Ghagar, once a tributary of the Hakra, rises within the Sirmur State in the hills to the east of Kalka. A few miles south of Kalka it crosses a narrow neck of the Ambala district, and the bridge on the Ambala-Kalka railway is in this section. The rest of its course, till it loses itself in the sands of Bikaner, is chiefly in Patiala and the Karnal and Hissar districts. It is joined by the Umla torrent in Karnal and lower down the Sarusti unites with it in Patiala just beyond the Karnal border. It is hard to believe that the Sarusti of to-day is the famous Sarasvati of the Vedas, though the little ditch-like channel that bears the name certainly passes beside the sacred sites of Thanesar and Pehowa. A small sandy torrent bearing the same name rises in the low hills in the north-east of the Ambala district, but it is doubtful if its waters, which finally disappear into the ground, ever reach the Thanesar channel. That seems rather to originate in the overflow of a rice swamp in the plains, and in the cold weather the bed is usually dry. In fact, till the Sarusti receives above Pehowa the floods of the Markanda torrent, it is a most insignificant stream. The Markanda, when in flood, carries a large volume of water, and below the junction the small channel of the Sarusti cannot carry the tribute received, which spreads out into a shallow lake called the Sainsa _jhil_. This has been utilized for the supply of the little Sarusti canal, which is intended to do the work formerly effected in a rude way by throwing _bands_ or embankments across the bed of the stream, and forcing the water over the surrounding lands. The same wasteful form of irrigation was used on a large scale on the Ghagar and is still practised on its upper reaches. Lower down earthen _bands_ have been superceded by a masonry weir at Otu in the Hissar district. The northern and southern Ghagar canals, which irrigate lands in Hissar and Bikaner, take off from this weir.