352 



ON THE METEOROLOGY OF IRELAND. 



I have selected for this purpose the results of the observations with 

 Lind's anemometer, made at Portrush and Donaghadee by two of 

 the best of the Coast-guard observers, and have placed my own 

 beside them, for comparison. The results, converted into pressures 

 (expressed in pounds on the square foot) are contained in the fol- 

 lowing Table. The numbers in the last column are the calculated 

 pressures, deduced from the formula 



P = Ptf, 



n being the number of the term of the scale, and P 1 ( = 0'30) the 

 pressure corresponding to the first term. 



PRESSURES or THE WIND CORRESPONDING TO THE TERMS or THE 



SCALE (0-6). 



It will be seen, that the differences of the corresponding num- 

 bers at the three stations are small, and that their means agree 

 very well with the calculated pressures. It seems, therefore, to be 

 fully proved that the velocity of the wind may be estimated to six 

 degrees, by practised observers, with sufficient accuracy. 



In the following Table are given the results of the observed 

 wind-force for the entire year, and for its two principal divisions. 

 The excess of the force in winter appears at all the stations, ex- 

 cepting Dublin, Portarlington, andAthy.* At these three stations, 

 also, the force of the wind is below the average. 



The mean force for the entire year is 1'76, corresponding to a 

 velocity of 20'4 feet per second. The force is, of course, greater in 

 winter than in summer, the mean force for the winter half-year 

 being 1*87, and that for the summer half-year 1'65. 



* Buncrana is likewise an exceptional case ; hut the exception is there probably due 

 to inaccuracy of observation. 



