“ Like other deltaic distributaries, they are subject to sudden changes in their channels, and to constant silting up. The supervising and keeping open of the Nadia rivers, therefore, forms one of the great tasks of fluvial engineering in Bengal. ”

“ This consists of the head-wave of the advancing tide, hemmed in where the estuary narrows suddenly into the river, and often exceeds 7 ft. in height. It is felt as high up as Calcutta, and frequently destroys small boats. The difference from the lowest point of low-water in the dry season to the highest point of high-water in the rains is reported to be 20 ft. 10 in. The greatest mean rise of tide, about 16 ft., takes place in March, April or May—with a declining range during the rainy season to a mean of 10 ft., and a minimum during freshets of 3 ft. ”