The lollowing is a Table of the increase of the Ganges and its branches.
_ These observations were made in a season, when the water rose higher than usual, so that 31 feet may be taken as the mean increase. Some days before the middle of August, the inundation is at a stand, and begins to run off, although great quantities of rain fall in the low countries during August and September. The daily decrease, in the latter end of August and all September, is from three to four inches. From this to the end of November, it lessens gradually to one inch and a half; from this to the latter end of April, half an inch on an average. The de crease of the inundations does not always keep pace with that of the river ; but after the rain has nearly ceased in the beginning of October, the remainder passes off quickly, chiefly by evaporation, leaving the land richly manured.
It is a fact, confirmed by repeated experiments and observations, that from the place where the tide com mences at the sea, the height of the periodical increase diminishes gradually, until it totally clisappeals at the point of confluence.
The quantity of water discharged by the Ganges in one second of time, during the dry season, is 80,000 cubic feet ; but the river taken full, having thrice the volume of water in it, and its motion being also accele rated as five to three, the quantity discharged is then 405,000 cubic feet. If the medium of the whole year be taken, it will be neatly 180,000 cubic fcct in a se cond.
The Burrampooter, for 60 miles from its junction with the Ganges, is from four to five miles in bt eadth. This great breadth, it is conjectured, may have Leen formed when the Ganges joined, where the 'smutty now does. In tlie remz:ining 340 milcs of its course in the pro‘itice of Bengal, it in many cspects resembles the Ganges; its whole length teckoned mere than that ri%cr, and their sources ale at no great distance. When they unite below Luckipoor, they produce a stream not equalled in the old hemisphere, and in rainy seasons render the sur face of the sea fresh for many leagues.
In the channels between the islands at their mouth, the bore rises from 5 to 12 feet ; after the tide is fairly past the islands, no vestige of the bore is perceived. In the Hoogley river, the bore commences at Hoogley point ; it is visible above Hoogley Tower, about 26 miles below Calcutta ; and the motion is so rapid, that it scarcely takes four hours between them. At Calcutta it some
times occasions an instantaneous rise of five feet. The boats generally make for the middle of the stream.
From October till the middle of 'March, when the north winds begin to blow, the rivers are in a tranquil state. The winds arc more violent in the eastern than the western parts of Bengal ; they happen most frequently towards the close of the day ; they arc preceded by irre gular coloured clouds in the latter end of May and be ginning of June. From the beginning of November to the latter cnd of May, the usual rate of going with the stream is 40 miles per day in 12 hours ; and during the rest or the year from 50 to 70 miles. The current is strongest in part of August and September, while the inundation is running off. The motion acquired by using oars in a large buclgerow hardly exceeds eight miles per clay. A budgerow is a travelling boat, with a cabin 14 feet wide, and proportionally long, and draws from lour to five feet water. In towing against the stream, the side is generally preferred where the banks are steep, on account of the greater depth of the water ; and from 17 to 20 miles per clay is the greatest distance passed over ; and, to accomplish this, the boat must be towed at the rate of 4a miles per hour for 12 hours. During the in undations greater progress can be made, because angles can be cut off, and sails used.
Calcutta is situated upon the Hoogley river, 100 miles from the sca ; it is navigable up to the town by the largest ships which visit India. The largest boats upon the Ganges vary from 300 to 600 maims, and their hire is from 20 to 30, or even to 60 rupees per month. A budgetow for gentlemen and their families, having from 3 to 24 oars, are hired, for the smallest 60 rupees, for the largest 230, per month. Upon the whole, by these two great livers, every part of the province of Bengal, with a few exceptions, Ivas, even during the dry seasons, a na vigable streant within 25 miles, and generally much less. All the salt, and much of the food, for ten millions of people, also exports and imports to the value of two mil lions sterling per annum, besides interchanging manu factures, fisheries, and travelling, employ upwards of 30,000 boatmen.