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Part III. — Seventh Annual Report 



the early part of October 1888 may be summarised briefly as follows : — 

 The densest water met with during the cruise was the bottom water 

 collected at Stations XXV., XXVL, XXVII., and XXVIIL, along a line 

 running eastwards from Balta Sound. North Unst, Shetland, to the 

 coast of Norway. At the two central stations the density was slightly 

 higher than that collected at the two outlying stations, being 1026*15 at 

 Station XXVL and 1026-16 at Station XXVII., as against 1026-09 at 

 Station XXV., nearest the Shetlands, and 1026*14, at Station XXVIIL, off 

 the coast of Norway. 



At the surface along the same line the density decreased from west to 

 east, that is, as the coast of Norway was approached, falling from 1026*11 

 at Station XXV. to 1022-5-4 at Station XXVIIL, where the surface 

 current of light warm water due to the outflow from the Baltic was first 

 met with — the most rapid fall (1025-54 to 1022-53) being between Stations 

 XXVII. and XXVIIL 



At Station XXL, in Lerwick Bay, the density at the surface was 

 1026*08 at high water and 1026-04 at low water. This gives an 

 indication of the slight extent to which the density of these waters 

 is influenced by the fresh waters contributed by the Shetlands, the 

 influence of fresh land water being greatest at the surface and at low water. 

 It should be noted that the results obtained by the hydrometer are not 

 sufficiently accurate to show this difference which undoubtedly existed. 

 If the slight difference between the two hydrometer readings (Table I.) 

 were supposed to have any meaning, which it has not, one might be 

 led to suppose that the density of the surface water in Lerwick Bay was 

 greater at low water than at high water. The density of the sea water at 

 Stations XV. to XX., near the Orkney Islands, was remarkably uniform 

 from surface to bottom, and ranged from 1025*89 to 1026*03. It was 

 therefore intermediate between the density at the Shetland stations and 

 that of the water lying off the east coast of Scotland, where the density 

 never reached 1026*00 even at the bottom. The highest densities observed 

 off the coast of Scotland were 1025*74 at the bottom at Station IV., near 

 the Isle of May, 1025*73 at Station VIIL, and 1025*73 at Station XII., 

 in Bervie Bay. 



Going southwards along the coast of Norway the density varied greatly, 

 being naturally very low at the surface in the fiords — 1021*45 at Station 

 XXIX., Hielte Fiord, and 1010*79 at Station XXX., in By Fiord. But 

 at both these stations water was found at the bottom only slightly less 

 dense than that met with out at sea. 



As the Baltic was approached, the influence of the fresh water flowing 

 out from it, became more and more marked at the surface, the density 

 falling from 1024*68 at Station XXXIII. to 1023*73 at Station 

 XXXIV, off the Naze, and to 1014*29 at Station XXXV., in the 

 Cattegat. At the bottom on the other hand the influence of the Baltic 

 outflow did not become marked till the shallow water of the Cattegat was 

 reached, the density being 1024*18 at Station XXXV., while at Stations 

 XXXIII. and XXXIV. it was 1025*87. 



The .lowest densities observed during the whole cruise were at Station 

 XXXVIIL, in the Baltic where the density fell to 1005*42 at the 

 surface and 1005*48 at the bottom. At this point, therefore, the sea 

 water finding its way along the bottom into the Baltic, was mixed with 

 about four times its volume of the fresh Baltic water. 



On the homeward passage from the Skaw to the Isle of May, water was 

 found at the bottom only very slightly less dense than the bottom water 

 about 200 miles further north, being 1025*97 at Station XLIII. as against 

 1026*16 at Station XXVII. At the surface, on the other hand, the 



