292 RESULTS. OF THE METEOROLOGICAL OBSERVATIONS TAKEN DURING 



It will be observed that there is a distinct tendency for the wind to veer (using the 

 term with reference to wind circulation in the soutliern hemisphere) during the fore- 

 noon, and to back during the afternoon and evening hours. This effect is most 

 pronounced in Spring and Summer, while in Winter it may be said to practically 

 disappear. A curious feature in Spriug and Summer is that both S.W. and N.E. winds 

 attain their maximum frequency at noon, the minimum in N. W. and W. winds being 

 recorded at this hour. The variation is most pronounced in Summer when the solar 

 effect is at a maximum. 



Cape Pembi'oke Lighthouse is situated at the eastern extremity of a narrow 

 peninsula running east and west, almost wholly composed of sand dunes, which absorb 

 the sun's heat by day and are subject to strong radiation at night, which doubtless 

 strongly influences the direction of the wind, owing to the unequal heating of the land 

 and the contiguous water surfaces, the effect being probably increased by the land mass 

 of the Falklands lying to the westward. 



Force of the Wind. 



The diurnal variation in the force of the wind may be gathered from the following 

 tal)le, the scale being the usual one, varying from to 12 : — 



Spring . 

 Summer 

 Autumn 

 Winter . 



Year 



8 P.M. 



4'5 

 4-3 

 4-4 

 4-3 



4-4 



Mid- 

 night. 



4-5 



4-4 

 4-2 

 4-1 



4-3 



Mean. 



4-4 

 4-4 

 4-4 

 4-2 



4-4 



Hence, except in Winter, the diurnal variation is well marked, and is most pronounced 

 in Summer, the wind force being greatest about or a little after noon, and least in the 

 early morning hours. 



On the mean of the two years the months with the maximum wind force are March 

 and December with a mean of 4'6, while June, July, August, and November have the 

 lowest wind force, viz. 4'1. On the whole. Summer is the stormiest time, and in Winter 

 the wind force is lowest ; but the variation between the seasons is very small. 



With regard to gales of force 8 or upwards, the number of cases in which this 

 value was attained at any of the six hours of observation were jiicked out for the 

 different directions, with the following results, — the numbei' of times force 10 was 

 recorded being given for comparison : — 



Force 8 or above 

 Force 10 



