2. Annicut. Sinking blocks for foundation of main wall with Fouracres' Excavator.
Medium: Photographic print
Photograph from the Crofton Collection: 'Public works including the Manora Breakwater and the River Son canal system' taken in 1871. The Son, a tributary of the river Ganga, passed through Bihar and was liable to flooding in the monsoon. An annicut, or weir was built on the Son between 1869 and 1875 by constructing a mass of rubble stone masonry founded on shallow wells. It is 12,469 feet long and consists of scouring sluices positioned at each flank which are fitted with gates which can be opened or closed at any state of the river other than high flood. Through these the gates the level of water in the pool above the weir can be kept at the height required to supply the canals that branch off from the dam and traverse the plains. The system to control the level of the river was devised by C. Fouracres.