SEA-FISHERIES LABORATORY. 331 



vigour independently, and such variations will naturally 

 affect the character of the composite Gulf Stream Drift. 



Four chief cases can be anticipated according as 

 either one or both of the circulations are strong or weak : — 



(a) Southern circulation (and Gulf Stream) strong; 



northern circulation (and Labrador Current) 

 strong. 



(b) Southern circulation weak; northern circulation 



weak. 



(c) Southern circulation strong; northern circula- 



tion weak. 



(d) Southern circulation weak; northern circulation 

 strong. 



I consider that to each of the above four types of 

 oceanic circulation correspond definite meteorological 

 conditions, and that the latter, in so far as they affect 

 the succeeding summer can be foreseen from the value 

 and time of occurrence of the maximum salinities — 

 especially on the line Holyhead — Calf of Man — in the 

 Irish Sea. 



Type (a) will probably be the most general,. 

 There will be a maximum salinity on the line 

 Holyhead — Calf of Man of about 34'4 in February. 

 This type will probably be associated with the usual kind 

 of somewhat variable English summer. The conditions 

 during 190T and 1908 seem to have corresponded to this 

 type. 



When the oceanic circulation is of type (6) less 

 water of high salinity reaches our shores from the 

 Atlantic, so that a salinity maximum of only about 34'2 

 is reached (on Holyhead — Calf line), and that not before 

 May. The years 1909 and 1910, with their dismal 

 summers characterised by little sunshine and much rain 





