~Action of Torrents.~--The Ghagar is large enough to exhibit all the three stages which a _cho_ or torrent of intermittent flow passes through. Such a stream begins in the hills with a well-defined boulder-strewn bed, which is never dry. Reaching the plains the bed of a cho becomes a wide expanse of white sand, hardly below the level of the adjoining country, with a thread of water passing down it in the cold weather. But from time to time in the rainy season the channel is full from bank to bank and the waters spill far and wide over the fields. Sudden spates sometimes sweep away men and cattle before they can get across. If, as in Hoshyarpur, the _chos_ flow into a rich plain from hills composed of friable sandstone and largely denuded of tree-growth, they are in their second stage most destructive. After long delay an Act was passed in 1900, which gives the government large powers for the protection of trees in the Siwaliks and the reclamation of torrent beds in the plains. The process of recovery cannot be rapid, but a measure of success has already been attained. It must not be supposed that the action of _chos_ in this second stage is uniformly bad. Some carry silt as well as sand, and the very light loam which the great Markanda _cho_ has spread over the country on its banks is worth much more to the farmer than the stiff clay it has overlaid. Many _chos_ do not pass into the third stage, when all the sand has been dropped, and the bed shrinks into a narrow ditch-like channel with steep clay banks. The inundations of torrents like the Degh and the Ghagar after this stage is reached convert the soil into a stiff impervious clay, where flood-water will lie for weeks without being absorbed into the soil. In Karnal the wretched and fever-stricken tract between the Ghagar and the Sarusti known as the Naili is of this character. ~The Jamna.~--The Jamna is the Yamuna of Sanskrit writers. Ptolemy's and Pliny's versions, Diamouna and Jomanes, do not deviate much from the original. It rises in the Kumaon Himalaya, and, where it first meets the frontier of the Simla Hill States, receives from the north a large tributary called the Tons. Henceforth, speaking broadly, the Jamna is the boundary of the Panjab and the United Provinces. On the Panjab bank are from north to south the Sirmur State, Ambala, Karnal, Rohtak, Delhi, and Gurgaon. The river leaves the Panjab where Gurgaon and the district of Mathra, which belongs to the United Provinces, meet, and finally falls into the Ganges at Allahabad. North of Mathra Delhi is the only important town on its banks. The Jamna is crossed by railway bridges between Delhi and Meerut and between Ambala and Saharanpur.