16 
On the Tides of the River Huglu 
[Jan. 
very' ' far f rom* 'being general to nUthe 
creeks of the Sunderbunds, and to the delta streams of other large rivers, ke 
thecreeks^ are sufficiently extended , and others converge too rapidly in . section m 
a low of it. This circumstance is of most common occurrence in those creeks 
S possess the great uniformity of section throughout their lengthened course , 
such as P the deserted outlets of the main river by which there is now no discharge . 
also in those creeks which terminate in large j’heelsor salt marshes, such as 
salt water lake in our own vicinity. In this lake, the point of dissipation is | 
attained in every state of the tide, a trifling daily fluctuation being sensible at the 
remotest extremity of the lakes, in the seasons when the bay tides are the greatest in 
quantity. This may be perfectly understood by the diagram, where, supposing A B J 
variable, it is evident that the distance to 0 must vary with it, and most probably 
the elevation of 0 above O also in the same ratio. Indeed this last appears very 
evidently to obtain in the lake, and in many other cases that 1 have met with, not 
excepting the river Hugli, where in the immediate neighbourhood of the tide limit 
or point 0, a very sensible fluctuation is perceptible between the neap tides and 
spring tides, and no sensible daily fluctuation, except occasionally in spring tides. 
It is much to be regretted that no observations exist lo guide us to the perfect de- 
velopement of the whole problem in the river Hoogly. Perhaps some of your many 
correspondents will be induced to supply what is most particularly wanted, namely, 
the exact position of the. 0 under all different circumstances of time and season, 
beside a few registers of daily tide at intermediate points, such as Chiusura and Sook- 
sagur, or Bdnsbaria. 
I subjoin, what perhaps may be interesting, a diagram of the state of the tides at 
Calcutta in the river and lake, compared with those at the mouth of the river at 
S&gar island, for the month of January (fig. 4) ; also a diagram for August, the 
extreme of the freshes, (fig. 5.) 
The tides are, each, general means of the whole months, and they have been re- 
duced to their relative level, agreeable to the scheme of connection, given by the 
dotted base to niv former chart. No. 2 . 
__ - - - ' O 
dotted base to my former chart, No. 2. 
Comparative lth*?ej#r Jan&an 
^7 
5 . 
fc.fr.! 
4 
tbe T !fvet l0 St to bJ ,°m P roU «“ in »« <***. and also stow what 
up-land water is to lie calculated' 6 Vm ' i "' ° r fron ! wllich tllu discharge 
descent of 4 ft. 3i n for the whole dUt Ja jua f y, the path of mean level shov 
mile. In A ugust the decent is 8 ft. 9?m '™" ,d « iv * ?. 1,,ches 
mile. In A u^stVe dSLm b 8 ft ^ of . 62 which would gives tuck 
than double what it is in January a ^°P e of 1,/ in. per mile, or t 
mouth and at Calcutta is semildv 'oportion also between the tide at 
August. ’ 18 Sensib, y dlmini ^ed by the raising of the mean lev 
creek* h isnot% d redify tim^ame or mouth of »he Mi 
in January, and in the dry months it hero tlde ’ although it cannot differ i 
of what is given as the elevation of f ?, C ° mes “ c , essar y to deduct a certain ,<o 
August. The descent,!,, Januay of the 1 t,dc at , S '« i ‘r, due to the sea- 
anuciy, ot the lake mean path is 3ft. lin., while in A 
