THE METEOROLOGY OF EDINBURGH. 79 



the greatest number being 1872, when twenty were experienced. During that year 

 pressure was lower and the rainfall greater than in any other year, with perhaps the 

 exception of 1789. Only one thunderstorm was recorded in the years 1773, 1780, 1784, 

 1796, and 1801. During comparatively recent years, 1844, 1851, 1859, and 1865 

 had two, but there is no record of a year without any. The months with the 

 greatest number of thunderstorms were August 1831, and July 1893, which had 

 eight each. 



Thunderstorms appear to be on the increase, the mean number from 1770 to 1809 

 being 4*5 per annum. In the forty years ending with 1849, the number rose to 6*3 per 

 annum, while during the period 1850 to 1889 a further increase to 9 per annum was 

 recorded. During the six years ending with 1895, the mean annual number was ten. 

 The increase can hardly be accounted for by the assumption that the early observers 

 systematically neglected to record this meteor. Only for about twenty years are we 

 dependent on one weather register for our information. 



The annual totals have been smoothed by Bloxam's method, taking continuous sets 

 of five. The results were projected on a chart which was originally prepared in connec- 

 tion with a paper on " Sunspots and Auroras." On comparing the two curves, little of a 

 definite nature can be made out, it being very doubtful whether thunderstorms are 

 phenomena of a fortuitous nature or are in some way connected with sunspots. There 

 is some reason to think thunderstorms are subject to a long cycle, a wave crest of which 

 we have lately passed. The wave shows distinct minima in 1802 and 1864, and maxima 

 in 1829 and 1882. 



With the view of ascertaining the damage done by thunderstorms to life and 

 property, every instance of a severe storm was examined, the newspaper reports for the 

 days characterised by disturbances of an exceptional nature being extracted. The result 

 of the inquiry is, that damage to property took place in thirteen thunderstorms, twenty- 

 six people in all being injured, and only two killed. Of the very severe thunderstorms, 

 seven occurred in June, three in July, two in August, and one in January, the latter 

 occurring on January 26, 1792, when George Watson's Hospital was struck. 



The worst storm on record appears to have been that of July 22, 1873, when an 

 observer of the Scottish Meteorological Society counted in one hour 680 flashes of light- 

 ning with their accompanying thunder-claps. This gives a rate of fully eleven per minute. 



During recent years, the severest storm experienced was that of August 12, 1884, 

 when the Earl of Lauderdale was killed. For notices of these storms see Appendix. 



Snow. 



Table XXXVIII. gives the number of days on which snow fell for each month, 

 and the year from 1770 to 1896. Values are also given showing the results grouped 

 by winters, with date of first and last snowfall. The total number of days on which 

 snow fell was 2664, giving an average of 21 per annum. The snowiest year was 1782 



VOL. XXXIX. PART I. (NO. 6). P 



