The Ganges, after winding amongst rugged mountains for about 800 miles, rushes through a rocky chasm at Hurdwaar or Harcloar, in Lat. 30°. It afterwards tra verses the plains of Hindostan by a course of about 1350 miles, in which it receives eleven rivers, several equal to the Rhine, few less than the Thames. From Hurd waar to Jumnah, about 750 miles, its breadth varies from a mile to a mile and a quarter, from thence downwards the channel becomes widcr : above the junction of the Jumnah, it is in some places fordable, but the navigation is never interrupted. Below this junction it acquires more depth than breadth. At 500 miles from the sea, the channel, in the lowest state of the river, is 30 feet deep, and continues so to the sea, except where the ve locity is checked by sand banks, thrown up by southerly winds.
The head of the Delta is at 200 miles from the sea in a direct line. The two western branches (the Cossom buzar and Jellinghey rivers) unite and form thc Hooglcy river, which is the port of Calcutta, and the only branch of the Ganges usually navigated by large vessels. The Cossombuzar river is almost dry from October to May. And the Jellinghey river, although it has a stream the whole year, is sometimes unfit for navigation for two or three of the driest months. The Chomdah river, which separates at Maddapoor, and terminates at Houngatta, is the only subordinate branch at all times navigable. The palt of the Delta next the sea is a labyrinth of creeks; salt, except those next the principal branch. The chan nels which intersect it afford a navigation throughout the Delta. The tract, named the Sunderbunds, (or Woods) is equal to Wales in extent.
From Hurclwaar to the sea, has been considered as one uniform plane ; by order of Mr. Hastings, a section for 60 miles, parallel with one of the branches, was found to have a declivity of nine inches in a mile, reckoning in a straight line, but allowing for the winding less than four inches per mile. The mean motion, in dry seasons, is less than three miles per hour ; after the inundation, when the water is draining off, it is from five to six miles; there have been instances of from seven to eight miles. During eleven years, the head of the Jellinghey river has moved three-fourths of a mile farther down, and by sur‘eys taken nine years apart, it appeared that the breadth of a mile and a half had been taken away. A mile in ten or twelve years, is reckoned the usual en croachments, at the places where the current stiikes with the greatest force. There are many instances of total changes, not only in the branches, but over the whole river. The Cosa river, equal to the Rhine, once passed
Purneah, and fell into the Ganges opposite Rajemall ; its junction is near 45 miles higher up. Gour, the ancient capital of Bengal, stood on the bank of the Ganges; its ruins are near four or five miles from it. Along the coast of the Delta, not less than eight openings appear to have been alternately the mouths of the rivers. The banks of sand and meadows IlOW extend about 2.0 miles into the sca beyond the islands in the mouth of the Ganges, and in some places rise within a few feet of the surface of the water. There is no substance so coarse as gravel in the Delta within 400 miles of the sea.
The Ganges owes its increase as much to the rain that falls in the mountains contig,uous to its SOUVCCS, as to that which falls on the plains of Hindostan; for it rises 151 feet out of the 32, its total rise, by the latter end of June ; and the rains do not begin in the flat countries until about that timc ; in the mountains it begins in Apt il, and by the latter end of that month the river begins to rise, at first only one inch per day for the first lortnight ; it then gradually augments to two or three inches before any lain has fallen in the plains. When the rain becomes general, the mean increase is five inches per day. By the latter end of July, all the lower parts of Bengal, con tiguous to the Ganges and Burrampooter, are overflowed, and form an inundation more than 100 miles in length, nothing appearing but villages ancl (recs. The ground adjacent to the river is, for some distance, higher than that which is more remote, and sepurates the water of the in undation from that of the liver, until the latter ovel flows ; this higher giound is in some seasons covered one foot. The depth of the inundation be)ond the banks varies ; in some parts it is 12 feet ; but, at the height of the inun dation, the course of the liver is evident from its greater motion and muddy colour. The motion of the inunda tion does not exceed half a mile per hour.
It is calculated that dykes or ahove 1000 miles in length have been constructed to protect one particular district. Onc branch of the Ganges, na%igablc only during rainy seasons, is conducted 70 miles between 0%o of these dykes; and, when full, passengers look down upon the country. When the river is full, the tide cannot counteract the- downward current. It is not uncommoti for a strong wind to swell the waters two feet above the ordinary level, and has occasioned the loss of whole crops of rice. The inundations are navigable in all directions, in straight lines, and smooth water.