In the middle of the 18th century, at least three fair-sized streams flowed between the Rajshahi and Dhaka Divisions, viz., the Daokoba, a branch of the Tista, the Monash or Konai, and the Salangi. The Lahajang and the Elengjany were also important rivers. In Renault's time, the Brahmaputra as a first step towards securing a more direct course to the sea by leaving the Mahdupur Jungle to the east began to send a considerable volume of water down the Jinai or Jabuna from Jamalpur into the Monash and Salangi. These rivers gradually coalesced and kept shifting to the west till they met the Daokoba, which was showing an equally rapid tendency to cut towards the east. The junction of these rivers gave the Brahmaputra a course worthy of her immense power, and the rivers to right and left silted up. In Renault's Altas they very much resemble the rivers of Jessore, which dried up after the hundred-mouthed Ganga had cut her new channel to join the Meghna at the south of the Munshiganj subdivision.