6 12 



Proceedings of the Royal Irish Academy. 



may be approximately estimated from the Isothermal Charts, and lead to the 

 following rough corrections to be applied to the mean monthly temperature 

 for Blacksod so as to give the corresponding values for Clare Island : — 



January, 



0-0° F. 



July, . . 



0-0° F 



February, 



. -0-2 



August, 



o-o 



March, 



o-o 



September, . 



. + 0-4 



April, . 



. + 0-1 



October, 



o-o 



May, . 



. +0-2 



November, . 



. -0-2 



June, . 



. +0-1 



December, . 



o-o 



The differences for the means of maximum and minimum and the values 

 of absolute maximum and minimum would not necessarily be of the same 

 order. 



In consideration of the general scope of the work of the survey of Clare 

 Island the temperature statistics considered were the following : — 



A. The mean monthly temperature. 



The highest and lowest values recorded for the monthly means and 

 the years when such extreme values occurred. 



B. The mean monthly maximum temperature. 



The highest and lowest values recorded for the mean monthly maxi- 

 mum and the years when such occurred. 



C. The mean monthly minimum temperature. 



The highest and lowest values recorded for the mean monthly mini- 

 mum and the years when such occurred. 



D. The highest and lowest values of the absolute maximum temperature 



for each month and the years when such were recorded. 



E. The lowest and highest values of the absolute minimum temperature 



for each month and the years when such were recorded. 



The mean values were taken for a period of thirty-five years from 1871 

 to 1905. The Blacksod records did not extend over all this period, but the 

 values were worked up by comparison with the stations of Ardrossan and 

 Valencia. 



The highest and lowest values in each case were taken over a period 

 extending up to 1910 inclusive. 



The results are given in Table VIII. 



