103 MR. G. V. VERNON ON THE DIRECTION 



irregularities, I have referred them to the four principal 

 points only, assuming that — 



N. = iN.E. +N. +iN.W. 

 E.= iN.E.+E. +1 S.E. 

 S. = i S.E. +S. +1 S.W. 

 W. = i S.W. + W. + iN.W. 



The means of all the years then give 



N. = 68-6 ; E. = 74-o ; 8 = 105-8 ; W.= ii5-8, 



showing a gradual increase towards the W. The mean 

 yearly direction was S. 45° W., or exactly S.W. 



The maximum variation towards the W. occurred in 

 1857, ^^^ ^^^ ^- 74° ^-y ^^^ minimum in 1861, and was 

 S. 31° W., so that the range of the mean direction was 



43°. 



In the diagrams or wind-roses (Pis. VIII. & IX.), the 



mean amount of each wind, referred to each month sepa- 

 rately, can be seen at a glance ; and the relative areas of 

 the various diagrams also sliow the frequency of the oc- 

 currence of each wind during the year. All these diagrams 

 have been drawn to scale. 



In Table III. the amounts of each wind are given for 

 each meteorological season. We see in this Table that 

 S.W. winds predominate in the winter months, and, more- 

 over, blow upon more days in this quarter than in any of 

 the remaining quarters. 



In the spring quarter the N.E. and S.W. predominate, 

 and are nearly equal : the N.E. wind blows upon more 

 days this quarter than in any other quarter. 



In the summer quarter the S.W. wind blows upon the 

 greatest number of days ; next comes the N.W. wind, which 

 has a greater prevalence this quarter than in any of the 

 other three quarters. 



In the autumn quarter the S.W. is the most prevalent 

 wind; then come the W., S., S.E., N.E., and N.W., which 



