THE METEOROLOGY OF EDINBURGH. 



77 



A disturbing element is introduced owing to some observers entering calms and 

 variable winds, whilst others always give a direction, which in still weather was probably 

 the point from which the wind last blew. Tables XXXIV. and XXXV. were accordingly 

 prepared so as to make the results as uniform as possible. In these tables the percentage 

 frequency was resolved to two directions as described above, calms being eliminated. 



Looking at Table XXXV., it will be seen that the years with the greatest percentage 

 of west wind were 1854, 1887 and 1798, with values of 791 per cent., 77*8 per cent., 

 and 76 "2 per cent, respectively. 



The effect of wind upon the temperature of the air is very apparent. Thus, in 

 1854 the mean temperature was above the average in every month, and in 1798 in ten 

 months. In 1887 the excess was not so noticeable. The years with the greatest per- 

 centage of east wind were 1768, 47*5 per cent.; 1829, 47*3 per cent.; and 1816, 46*0 

 per cent.; the prevalence of polar winds, as was to be expected, resulting in a marked 

 fall of temperature during these years. 



Mean Relative Humidity. 



The mean relative humidity has been determined from the bi-daily observations 

 made with the dry and wet bulb thermometer, the hours of observation being 9 a.m. 

 and 9 p.m. The period under discussion is the thirty-five years 1862-1896. The mean 



Mean Relative Humidity, 1862-1896. 



Month. 



Mean. 



Highest. 



Year. 



Lowest. 



Year. 



Range. 





% 



% 





% 





% 



January, 



86-8 



96 



1879 



81 



j 1895 



\ 1896 



1895 



1868 

 J 1868 

 \ 1896 



15 



February, 



March, 



April, 









86-4 

 84-1 

 80-5 



97 

 96 

 93 



1879 

 / 1871 

 \ 1879 



1872 



78 

 77 

 73 



19 

 19 

 20 



May, . 









78-1 



92 



1872 



72 



1881 



20 



Juue, . 









77-4 



94 



1875 



67 



1884 



27 



July, . 









79-1 



85 



1870 



74 



/ 1869 

 | 1878 



11 



August, 









81-5 



90 



1877 



74 



1869 



16 



September, 









82-6 



92 



1875 



74 



1869 



18 



October, 

 November, 









85-8 

 86-8 



92 

 94 



1882 



/ 1876 



\ 1881 



1876 



f February 



\ 1879 



80 

 78 



f 1867 



I 1892 



1869 



12 

 16 



December, 

 Year, . 









86-4 

 83-0 



92 



97 



83 

 67 



1867 

 J June 



\ 1884 



9 

 30 



annual humidity is 83 (Saturation = 100). The air is driest in June, which has a mean 

 humidity of 7 7 '4 per cent., and dampest in January and November with 86'8 per cent., 

 the range being thus 9*4 per cent. As regards individual months, the dampest was 



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