524 



MR RANKIN ON GALES OBSERVED AT BEN NEVIS OBSERVATORY. 



the westward. The hourly variation shown in this table indicates a diurnal pulsation 

 in the intensity of the wind of these cyclonic areas of a complex character, and this 

 during the winter months, for there are too few cases in the summer to seriously affect 

 the annual hourly values, or indeed to give a satisfactory average for any month from 

 May to September. 









Number 



OF 



Gales (Force 6*5 . 



4.ND 



ABOVE), 



1884 to 1896 



INCLUSIVE. 











Hours. 



1 



2 



3 



4 



5 



6 



7 



8 



9 



10 



11 



12 



13 



14 



22 



18 

 11 



15 



16 



17 



18 



19 



20 



21 



22 



23 



24 



Totals. 



Jan. 

 Feb. 

 March . 



35 



18 

 22 



29 



20 

 18 



27 

 17 

 17 



30 

 23 



14 



27 

 17 

 14 



27 

 22 

 10 



32 

 24 

 13 



28 

 19 

 14 



30 

 24 

 15 



26 

 26 

 15 



33 

 22 

 13 



29 

 18 

 15 



25 

 19 

 15 



19 

 18 

 12 



21 



16 

 6 



23 

 15 



7 



26 



16 



9 



21 

 20 

 12 



23 



17 

 15 



22 

 23 



17 



26 



26 

 18 



28 

 26 

 17 



31 



25 

 17 



640 

 489 

 336 



April 



May 



June 



15 



7 

 7 



14 

 4 

 6 



12 

 5 

 6 



13 

 1 

 5 



13 

 1 

 5 



13 



4 

 5 



14 

 4 

 5 



15 



7 

 6 



14 

 6 

 5 



13 



4 

 3 



9 

 6 

 5 



11 

 6 

 3 



14 

 5 

 5 



11 

 

 3 



8 

 2 

 3 



10 

 2 

 2 



12 

 3 



1 



12 

 6 

 2 



8 

 8 

 3 



14 

 7 

 3 



12 

 9 

 3 



13 



8 

 4 



15 

 5 

 5 



16 



5 

 6 



301 

 115 

 101 



July 

 Aug. 

 Sept. 



3 

 6 

 3 



3 

 6 

 4 



2 

 3 

 5 



2 

 4 



5 





 4 

 5 







4 

 7 





 5 

 6 



1 

 6 



4 





 6 

 3 



1 



4 

 5 



1 

 5 

 5 





 3 

 6 



1 

 3 

 6 



2 

 4 

 6 



5 

 5 

 4 



3 

 3 

 6 



2 

 3 

 5 



2 

 6 

 4 



2 



6 



5 



4 

 5 

 5 



4 

 7 

 5 



3 



5 



6 



3 



5 

 4 



4 



8 

 4 



48 

 116 



118 



Oct. 

 Nov. 

 Dec. 



8 

 22 



18 



10 



21 

 18 



8 

 25 

 22 



7 

 26 

 16 



7 

 28 

 17 



10 



23 

 16 



8 

 26 



17 



11 

 27 

 19 



16 



26 

 18 



7 

 26 

 17 



10 

 24 

 17 



7 

 20 

 21 



7 

 24 



14 



5 

 21 

 13 



7 

 18 

 14 



6 

 19 

 15 



10 



17 

 12 



13 

 22 

 13 



13 

 17 

 14 



13 



17 

 11 



14 

 21 

 14 



12 

 17 



11 



11 

 19 



18 



13 

 20 



17 



233 

 526 

 382 



13 years . 



164 



153 



149 



146 



138 



141 



154 



157 



163 



147 



150 



139 



138 



116 



115 



109 



110 



131 



129 



134 



151 



149 



156 



166 



3405 



If the five months with low values, that is May to September, are grouped together 

 the total number of cases is 498, and these show in their distribution over the day a 

 double period of the same nature as that given by the annual totals. In the small 

 table below, the total cases are given : (1) for the five months, May to September, and 

 (2) for the remaining seven months, October to April. Both sets of figures show a 

 diurnal range with double maxima and minima. The highest and lowest hourly values 

 in the summer months are respectively 28 and 14, a ratio of 2 to 1 ; while in the 

 winter months these values are 143 and 93, a ratio of about 3 to 2. Thus the 

 proportional daily range is greater in summer than in winter, indicating that this, like 

 other diurnal meteorological changes, is due to solar action. 





1 



2 



3 4 



1 

 5 6 



7 8 9 



10 



11 



12 



13 



14 



15 



16 



17 



18 19 



20 



21 



22 



23 



Mid- 

 night. 



Totals. 



May to September 

 October to April . 



26 



138 



23 

 130 



21 17 

 128 1 129 



15 : 20 

 123 ( 121 



20 24 

 134 133 



20 

 143 



17 

 130 



22 

 128 



18 

 121 



20 



lis 



15 

 101 



19 

 90 



16 

 93 



14 

 96 



20 24 

 111 105 



24 

 110 



28 

 123 



26 

 123 



22 

 134 



27 

 139 



498 

 2907 



