18 S. R. Elson — On the Changes observed in the Density [No. 1, 



tliis spot, on the ebb tide. He was evidently not far wrong in his sur- 

 mises as to there being a something which assisted vessels to cross the 

 Gasper bar in safety. 



Ever anxious to learn something more of the causes of these /rea^5, 

 as some would call them, of the currents at the Sandheads, and of the vary- 

 ing specific gravity of its waters, on the 13th of November last T gladly 

 availed myself of an unexpected opportunity for further investigation 

 by taking serial observations of the sea-surface temperature and density 

 on some one line, or compass bearing, right off from the turbid water 

 of the Pilot, or Eastern Channel Light Station, out into the deep blue 

 sea of the Bay of Bengal. Nor, for my purpose, could it have occurred 

 at a better time, with regard to the relative state of the weather, when 

 going and returning, as will be seen. I went off S. E. towards Ran- 

 goon as acting special pilot in the B. I. S. N. Company*s 6 8. S. Sirsa and, 

 commencing at the Lower Saugor Sand buoy, which is about 5 miles 

 farther inshore and towards the land than the Eastern Channel Light 

 Vessel, I took observations with the bottle hydrometer, and thermo- 

 meter, every two hours, with the following results : — 



Temperature. Specific gravity. 

 Air. Sea. 

 November 13th, 1886 Noon, 2 miles S. W. 



from Lower Saugor Sand buoy ... 86° 83° l-009f| 

 At 2 p. M. 20 miles S. E. of E. C. Light 



Station ... ... 83-5° l-009y% 



At 3"30 p. M. Passed through a frothy 

 line of demarcation running E. and 

 . W. between light and dark green co- 

 loured water. 

 At 4 p. M. 45 miles on same line ... 81° 83° 1-021-^ 



1 6 



At 5-30 p. M. 60 miles on same line 82° 1-02244 



1 5 



November 14th 6 30 A. M. 200 miles on same 



line or in 19° 80' N. 91° 2' E. ... 81° 83° l-0223-«^ 



At Noon 265 miles miles on same line ... 81° 81-5° 1.022^^ 



At 5-30 p. M. 320 miles on same line ... 81° 82-5° l'023|f 



On this outward trip the ordinary fine weather of the winter mon- 

 soon prevailed, following a rather heavy cyclonic disturbance down the 

 bay : but on the return journey on the 20 th, 21st, and 22nd of the same 

 month there was a hard cyclone prevailing to the south, and then 

 southwest of the Hooghly Pilot Station ; and a strong set of the 

 sea up along the eastern side and, I suppose, the centre of the Bay 

 of Bengal, carrying the vessel I was on board of, the B. I. S. N. Company's 



