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



Temperature. Speciflc gravity. 

 Air. Sea. 



(After this I was absent from Sandheads 

 until the 13th.) 



On 13th November 1886, in nearly same 

 position, just after the cessation of the 

 strong westward set caused by a cy- 

 clonic whirl down the Bay, and all 

 was again quieted ... ... 86° 83° I'OOOlf 



On 22nd November, in same position, 

 during a severe and widespread cy- 

 clonic disturbance farther down the 

 Bay wMch had been some days in 

 existence : and when a strong north 

 westward set of the sea was pouring 

 in towards this position from, and 

 across, and most likely out of, the 

 depths of the peculiar sub-marine ra- 

 vine, or gut of deep, and (as Com- 

 mander Carpenter has told us) cold 

 water, called * The Swatch of No 

 Ground* ... ... ... 795° 795° 1-016,^ 



From the above, and what has been shown before, it seems the 

 fresher water setting from the eastward, off and on, ever since the 31st 

 of October (on the evening of which day the changed colour and appear- 

 ance of the sea alongside led me to test it, and I found a slight dimi- 

 nution in its density, even then), or for half a month, was completely 

 crowded out, as it were, by the last mentioned north-westward moving 

 current of the 20th, 21st, and 22nd of November : which the S, S. Now- 

 shera's log book furnishes ample proofs of ; and, as a consequence, the 

 salinity of the water at the station increased too, and probably, for a 

 ■while, exceeded its normal : but, on this point, the few observations I have 

 had opportunity to make and record will not permit me to write with 

 that degree of assurance that I should like to do. 



Maury says of the hydrometer : — ' In the physical machinery of the 

 universe there is no compensation to be found that is more exquisite or 

 beautiful than that which, by means of this little instrument has been 

 discovered in the sea between its salts, the air, and the sun : but Maury 

 could hardly have meant the instrument commonly found on shipboard, 



* For a description of which see paper by Commander Carpenter, R. N. (read 

 before your Society some time back). 



