SEA-FISHERIES LABORATORY. 211 



from the southern parts of the Irish Sea drifts northwards 

 and is eventually washed up on the coast of Lancashire 

 and Cumberland, that is to say, exactly where a current 

 from South to North, and passing to the East of the Isle 

 of Man, would be expected to take it. The same thing 

 almost invariably happened to bottles thrown overboard 

 by Professor Herdman.* 



Bearing these facts in mind, it seems somewhat 

 strange that anyone should assume that the flow of water 

 through the Irish Sea was in the contrary direction, 

 especially since, even neglecting the above-mentioned 

 facts, it was a priori improbable. 



It is well known (" Law of Ferrel ") that owing to 

 the circulation of water from the poles to the equator and 

 back to the poles, coupled with the rotation of the earth 

 about its axis, the marine currents in the Northern 

 Hemisphere tend to flow from S.W. to N.E. in the case of 

 warm currents, or from N.E. to S.W. in the case of cold 

 currents. 



The Gulf Stream is one of the former, and, as is well 

 known, flows round the North of the British Isles to the 

 Norwegian Coast. It has been known for several years 

 that a small branch of the Gulf Stream passes through the 

 English Channel, and it was to be expected also that some 

 of the eastward flowing water would succeed in forcing 

 its way through the Irish Sea. 



A current flowing southwards through the Irish Sea 

 might be one of two kinds. It might be a cold current, 

 which, however, would be flowing in rather the wrong 

 direction (namely, a somewhat easterly one) for a cold 

 current. It is, however, clear that it would be impossible 

 for such a cold current to get down the Irish Sea, for to 

 do so it would first have to cross the Gulf Stream flowing 



* Trans., Biol. Sog. of Liverpool, XVII., p. 154 (1903). 



