i62 A TEXTBOOK OF OCEANOGRAPHY 



is a cyclonic circulation in the iipper surface waters of the 

 North Atlantic. This is established not only by water 

 températures and salinity, but by drift-bottles as well. 



Floating bottles from Franz Joseph 's Fiord in East Green- 

 land hâve been picked up in North-Western Ireland and the 

 Hébrides, The velocity of the current in this circulation is 

 extremely slight, and on the average attains lo miles per day. 



Counter-currents occur, and this makes the identification 

 of the circulation difhcult. A more detailed considération of 

 this area is given elsewhere (p. 190). 



The gênerai easterly drift in the North Atlantic produces 

 an east-going current at the entrance to the Bay of Biscay. A 

 Biscayan current was first described by Rennell in 1793, and 

 was known as Rennell Current. It was stated by Rennell to 

 run along the north coast of Spain across the French coast 

 to the north and north-west, and thence straight across the 

 entrance to the English and Bristol Channels. M. Hautreux 

 proved from a large number of drift-bottle experiments that 

 this current does not exist ! Probably in the Bay of Biscay 

 the currents follow the wind. 



There appears to be a current running east or east-south- 

 east into the Bay, since a large number of drift-bottles are 

 washed up betweén the Loire and the Gironde, most of which 

 come from the north-west — that is, exactly opposite to the so- 

 called Rennell Current. On the other hand, not a single bottle 

 thrown out between Ushant and Finisterre was recovered from 

 a north-westerly direction. 



Reports collated from sailing vessels show, in the western 

 half of the Bay of Biscay, a current in January running south 

 40° east, with a velocity of 127 sea-miles per day; and in 

 July south 30° east, with a velocity of 14' i sea-miles per day. 

 The stability or frequency is, however, small — in January 

 14 per cent, and in July 42 per cent. In the coastal régions of 

 the north of Spain there is an easterly current, especially in 

 winter; in summer, with a barometric dépression over Spain 

 and a north-east wind, the current runs west. 



