SEA-FISHERIES LABORATORY. 221 



early time of arrival and greater strength of the Gulf 

 Stream Drift in our area. After two successive years of 

 a late and weak Gulf Stream Drift associated with wet 

 and gloomy summers, we had in 1911 an early and 

 unusually strong invasion of Atlantic water in the Irish 

 Sea, followed by the exceptionally dry and sunny 

 summer. Under these unusual conditions we have 

 decided that this cannot be regarded as a normal year, 

 and that it is desirable to carry on the observations a 

 little longer in the nope of obtaining a greater uniformity 

 of results. 



We insert here for reference the chart (fig. 4) of air 

 and sea temperatures for 1911; and, for comparison, the 

 similar chart (fig. 5) of the previous year — both made 

 from the Port Erin Biological Station records by Mr. 

 H. C. Chadwick. It will be noticed that, compared with 

 1910, the sea-temperature in 1911 was lower in spring, 

 below 43° F. in the first week of April, but reached a 

 higher point in summer, over 59° F. late in August. 

 There was an almost uninterrupted rise in temperature 

 for five months, from March 25th (the lowest sea-tem- 

 perature of the year, 42° F.) to August 26th. In the air- 

 temperatures the highest weekly average was 63° F., and 

 an unusual number of records are above 60° F., one week 

 in June, two in July, and four in August. In 1910 only 

 one week (August) was over 60°, and in 1909 the highest 

 weekly average was 58° F. 



Sunshine. 



We are only concerned with the hours of sunshine in 

 so far as the record seems to show any co-relation with 

 the plankton. The summer of 1911 was a notable one 

 as regards amount of sunshine. In May, June, August, 

 mid September, the hours of sunshine at Port Erin were 



