COASTAL WINDS AND THEIR INFLUENCE UPON FISH. 37 



resort to complicated mathematical calculations or geo- 

 metrical construction in accordance with the principle of 

 the parallelogram of forces; the latter method, which for 

 convenience I have adopted, is with the exertion of care of 

 sufficient accuracy for the present purpose, and it needs 

 no detailed explanation. The yearly normal has been 

 obtained in a similar manner, and the results are illustrated 

 in Diagram O. (Plate II.) 



It will be noted that from November to March, the winds 

 blow persistently from the sea and during May to Septem- 

 ber in an almost opposite direction ; April and October are 

 peculiar to themselves, and of a neutral character. (In 

 this and the following wind diagrams the arrows point with 

 the wind). The yearly resultant or normal drift is inter- 

 esting as regards direction and extent, it is in accord with 

 the meteorologist's contention as regards the general 

 ingress of the lower atmospheric layers from the pole to 

 the equator, but it is contrary to a popular idea which is 

 based upon the importance of prevailing winds (with us 

 from the north-east). 



The yearly resultant coincides to within a couple of 

 degrees with the local magnetic deviation, and its relation- 

 ship to the coastline might be noted. The seasonal changes 

 already referred to are most apparent from Diagram D., 

 (Plate III); this is founded upon the monthly normal winds 

 from each point as recorded in Table VI., the arrow on the 

 cardinals being proportionate to the mileage. The interven- 

 ing areas have been coloured simply to assist the eye and 

 are not otherwise representative. The central figure repre- 

 sents the normal year's winds, and has been divided into two 

 sections — red and green — by a line along the direction of 

 the average atmospheric drift already described, the mar- 

 ginal figures which represent the different months as named, 

 have also been divided by lines parallel to the yearly drift. 



