16 S. R. Elson — O71 the Changes ohserved in the Density [No. 1, 



between these westward flowing waters outside, and those situated 

 under the lee of Saugor and Edmon stone Islands, and their continua- 

 tions, as outlying, partially dry, sands, to the northwards, will be alter- 

 ed, as I shall presently endeavour to show. 



As an instance out of many I have known of the suddenness of a 

 change of this sort : — At 1-30 p. m. of the 10th of August last, I found 

 the sea at the Pilot Station registered a specific gravity of 1'024 : but 

 only four days afterwards, at the same hour with regard to the tide, and 

 almost in the same position, it was only I'OlSy^Q- or was 'OlOy^ less 

 salt. But gradually, during these four days, a westward set of the sea 

 hereabouts had got up, which steadily increased until it was running 

 at the rate of two miles an hour or more, and, as is always the case, its 

 presence was unmistakably announced by a rather sudden change in the 

 colour and appearance of the sea (in fact, it was this marked change 

 that induced me to test the water again) , the water changing from a 

 wholesome sea-green to a yellowish (but not muddy or turbid) hue, or 

 of the colour of stagnant ditch, or tank water. 



But, generally speaking, after the westward set has run for some 

 time, this sickly looking water changes its appearance for the more 

 natural green. And, so far as my limited and solitary observations go 

 to show, the amount of salt increases as the westward set slackens. 

 Therefore, these intermittent incursions of greater or less supplies of 

 fresher water from, I suppose, the great easterly mouths of the Ganges, 

 must be taken into consideration, when making comparisons as to the 

 relative amounts of salt contained in the sea- water off, and in, the differ- 

 ent parts of the outlet channels of the Hooghly and its estuary. 



As I have said before, in a paper read before your Society some time 

 back, entitled * The Tides and Currents of the Hooghly &c., &c.,' none, or 

 but very little, of the water from the river Hooghly can possibly reach 

 the Pilot Station, situated as it is about 36 miles S. S. E. from Saugor 

 Roads, seeing that, by the direction vessels ride when at anchor, in all the 

 lower part of the river, from Mud Point to Saugor, the ebb tide sets 

 S. W. and S. S. W. away towards Balasore Roads, or Bay, which is an 

 extensive circular and shallow basin some 40 miles broad. Therefore, 

 Saugor Island and its outlying, partially dry reef, called Saugor Sand, 

 running down as it does over 22 miles S. S. E. from the tail end of 

 Saugor Island, whilst the over-active sun's rays are copiously extract- 

 ing vapour therefrom, must, and undoubtedly does, afford efficient shelter 

 to the muddier and semi-opaque, and therefore, warmer water on its 

 immediate westward side, from an early incursion of the above-men- 

 tioned drift of fresher waters, from the eastward, as, doubtless, the 

 following serial observations, carefully taken for the purpose, show. 



