THE METEOROLOGY OF EDINBURGH. 81 



Hail does not seem to be associated with thunderstorms, few cases being observed in 

 summer. 



Gales. 



Table XLL, showing the number of gales, must be looked on as a tolerable 

 approximation to the truth. As the entries depend on personal and not instrumental 

 observation, the results are not strictly comparable. The greatest number of gales was 

 seventy-two in 1818, and the least number, five in 1856. The mean annual number is 

 twenty-nine. 



Fog or Mist. 



This is also an unsatisfactory Table (No. XLIL), although every effort has been 

 made to eliminate entries of " haze " by comparing the Edinburgh records with those 

 from contiguous stations. The foggiest year was 1808, with thirty-eight entries, while 

 in 1784 no fog was reported. 



Auroras. 



Table XLIII. shows the number of auroras observed in Edinburgh from 1773 to 

 1781, and from 1800 to 1896. 



I have to thank Professor Copeland for permission to examine the records of the 

 Edinburgh Royal Observatory from 1862 to 1894. Many notices have also been 

 obtained from the published records of that institution. 



The year of maximum auroral frequency was 1871, with twenty-one auroras, closely 

 followed by 1870 with nineteen notices. The maximum observed in one month was six 

 in March 1871. 



Lightning. 



Table XLIV. shows the number of cases of lightning without thunder recorded 

 from 1807 to 1835, and from 1868 to 1896. During the other years this phenomenon 

 was not systematically recorded, as there are only about a dozen entries. The greatest 

 number of cases was six in 1818 and 1884. The maximum in any month was three in 

 February 1818, and again in September 1884. Sheet lightning is a comparatively 

 common occurrence in winter, being frequently seen during severe gales, especially when 

 accompanied by a low barometer. 



Hourly Sunshine Values. 



Table XLV. shows the distribution of bright sunshine throughout the day for the 

 months, seasons, and the year. The results are derived from the records of a Campbell- 



