SEA-FISHERIES LABORATORY. 263 



affects the plankton, practically a hoinotherniic and 

 homosaline water mass. 



Temperatures in April. 



The surface temperatures have been taken with 

 Eichter thermometers divided into rb~°C. and provided 

 with Charlottenberg certificates. The correction has been 

 applied in all cases. The deeper temperatures have been 

 taken with a Eichter reversing thermometer attached to 

 an Ekman Water-bottle. Two thermometers should be 

 used, or temperatures be taken twice at the same depth 

 (and not in succession), in order to check the readings, 

 since the best reversing thermometers may at times 

 prove fickle. For comparison there exist at present only 

 some records taken in recent years by Mr. Johnstone on 

 board the " James Fletcher " at two stations not far from 

 the Isle of Man, and a few taken by Mr. Drew on the 

 " Ladybird " during the summer of '08 at our two 

 Stats., I and III, lying 5 miles and 2 to 3 miles outside 

 of Bradda Head, respectively. 

 Stat. I. 5 miles N.W. Bradda — Corrected temperatures. 



April. 



TVnfVi 





5 



6 



7 



8 



9 



13 



14 



fathoms 



5 

 10 

 15 

 20 

 25 



7-10 



7-82? 



7-82? 



7-22 

 7-62? 

 7-87? 



7-52 

 7-12 



7-22 



8-15 

 7-62 

 7-18 



7-19 



7-92 



7-27 

 7-12 



7-17 



7-42 



7-23 



7-22 



7-62 



7-43 



7-42 

 7-37 







15 



19 



21 



23 



24 



20 







7-77 

 7-57 

 7-39 

 7-35 



7-32 



7-62 

 7-52 



7-48 

 7-48 

 7-48 



7-57 

 7-52 

 7-30 



7-64 



7-72 



7-65 

 7-67 

 7-67 



8-12 



5 







10 





7-78 



15 





7-78 



20 





7-70 



25 













