The Hydrography of the Faeroe- Shetland Channel 89 



surface a thin laj'er also moved southward ; this layer became thicker 

 on both sides, and near the Shetlands extended to the bottom. 



1900. — The whole channel is occupied by water from the south, 

 northward movement having apparently been strong earlier in the 

 season. At the date of the observations (July) little movement was 

 in progress, but there are indications of intrusion of water from the 

 north at a depth of about 300 fathoms, and at the surface on the east 

 side. 



1901. — There are indications of feeble southward movement in the 

 depth, but most of the channel is occupied by water which has come 

 from the south. A weak northerly movement is apparent near the 

 surface, with some tendency to split into two branches, one west of 

 mid-channel, the other near the east side. 



1902. — Unusually cold fresh water filled the channel, at all depths 

 below 150 fathoms, throughout the season. In May the surface 

 waters were of southern origin, and were moving northward, but as 

 the season progressed, southward movement increased both at the 

 surface and in the depth, especially in mid-channel, the waters mixing 

 with and driving out those of southern origin on each side. That this 

 movement extended far to the southward is shown by the fact that an 

 ice-floe was met with during July off the Treshinish Islands, on the 

 west side of Mull. The summer of 1902 was one of the worst on 

 record in the Faeroe -Shetland Channel, and hydrographical work was 

 exceedingly difficult. 



A comparison of the 1902 sections with the admirable charts of 

 surface temperature published as insets in the British ' Pilot Chart of 

 the North Atlantic ' shows in the clearest manner the relation between 

 the surface movements in the open ocean and the currents in the 

 channel. In May the surface temperature was normal, or slightly 

 below it, between the west coast of the British Isles and about Long. 

 15° W. Farther west, and to the north-west, there was a narrow band 

 of water above the normal temperature, obviously supplying the water 

 which was going northward on the east side of the channel. In June 

 temperature was apparently below the normal over the whole of the 



12 



