624 tnANS ACTIONS OF SEC'l^lON A; 



r.peli of belated or deferred summer Leat which was experienced at tlie end of 

 August and beginuing of September 1906. 



Such vagaries of the weather produce au extraordinary impreseiou on men's 

 minds, and on all sides we hear the remark, 'The seasons have changed. The 

 severe winters of long ago, with their snow and Ice, have disappeared; our 

 summers are cool and rainy, our winters mild and windy; our autumns are 

 warm and our springs are cold : in fact, there is a postponement of season, and 

 it is progressive.' 



The object of this paper was to test the accuracy of this popular opinion. 



Among weather records of a past age reference was made to the Rev. William 

 Merle's ' Consideraciones Temperiei pro 7 Annis' (1337-1344), from which it 

 would appear that the weather was much the same at Oxford and at Driby, 

 Ijincolnshire, in the fourteenth century as it is at present. 



The Greenwich records extend from the year 1774 to the present time. In a 

 paper based on the observations taken at Greenwich from September 1811 to 

 June 1856 inclusive, and read before the Royal Meteorological Society in Decem- 

 ber 1887, Mr. Henry S. Eaton concludes that ' there was no appreciable change 

 in the mean annual temperature of the air at Greenwich in the period 1812 to 

 1855 inclusive.' 



The late veteran meteorologist Dr. Alexander Buchan compared the mean 

 temperature of the British Islands, as recorded in the twenty-four years 1857 to 

 1880, with the mean for a much more extended period, and found that at none 

 of the British stations did the two values dift'er more than 0-3° F. 



In 1770 Dr. Thomas Rutty published a work of 340 octavo pages, entitled 

 ' A Chronological History of the Weather and the Seasons, and of the Prevailing 

 Diseases in Dublin.' The results of forty years' observations are recorded in this 

 volume. Rutty's remarks on the weather in Dublin in the early years of the 

 eighteenth century would serve to describe accurately the weather of the 

 twentieth century. This entertaining and instructive work teaches us that 

 beyond doubt the seasons were as often erratic in the eighteenth century as Ave 

 have found them to be in the nineteenth and twentieth centuries. Precisely the 

 same story is told in ' A Diary of the Weather and the State of Vegetation at 

 the Botanic Garden of the Dublin Society,' by .Tohn Underwood, A.L.S., head 

 gardener and superintendent during the years 1802-1808 inclusive. 



The remainder of tlie paper was devoted to an analysis of the observations 

 made personally by tlu; author from the year 1861 onwards to tlie ])resent. 

 His remarks were illustrated by four printed tables, setting forth respectively 

 the monthly and yearly mean temperature of the air, as well as tiio lustrum 

 averages, for the forty years 1860 Jo 1905 inclusive; the monthly and yearly 

 rainfalls and the rain days and the lustrum averages for the same pariod, and 

 rhe mean atmospheric pressure, with lustrum averages, in the forty years. 



The average annual mean temperature of the period 1866 to 1905 inclusi\e 

 in Dublin was 49°-7, tlie lustrum averages being 50"-l, 50°-2, 49'^-3, 49"-4, 48''-6, 

 49''4, 50°-8, and 50°. 



The highest annual mean temperature was 51 ^-O in 1898: the lowest was 47"-.". 

 in 1879 — the ' cold year.' 



A careful study of this temperature table shuws that, no matter what fluctua- 

 ( ions may take place between individual months in successive years, or between 

 individual years in successive lustrums, the temperature pendulum swings back 

 to its original position at either side of the average. 



The rainfall shows a variation from 45 per cent, in excess of the forty years' 

 average — 27672 inches — to 40 per cent, in defect. The extreme excess occurred 

 in 1872, when the rainfall was 35*566 inches; the extreme defect fell in 1887 — • 

 t^ueen Victoria's Jubilee year — when the measurement was only 16601 inches. 



The average annual number of rain days in Dublin is 196. In 1870 the 

 number fell to 145 ; in 1872 it rose to 238. 



Atmospheric pressure is on the average of the forty years 29-920 inches in 

 Dublin. The mean annual pressure varied from 29731 inches in 1872 to 

 30-015 inches iu 1887. The extreme readings of the barometer were 31-020 inches 



