ON THE METEOROLOGY OF IRELAND. 349 



It is not necessary to enter more minutely into the discussion 

 of the numbers of the preceding Tables, as it is probable that the 

 results of a single year, as to the frequency of the several winds, 

 will deviate considerably from the means of several. I may 

 observe, however, that they afford some indications of a law of 

 distribution, depending upon the aspect of the coast. Thus, on 

 comparing the numbers denoting the frequency of any particular 

 wind at the several stations, with their mean for the whole island, 

 it would seem that easterly winds are slightly in excess on the 

 western coast, and westerly winds on the eastern. In other words, 

 there appears to be a preponderating tendency of the wind to blow 

 front the tand, at each place, as compared with the mean of all. It 

 will remain for future inquiry to ascertain whether this holds good 

 in other years, and is, therefore, to be referred to a general law. 

 If so, it is probably the effect of the land and sea breezes, the 

 former preponderating in the average of the winds at 9 A. M. 

 and 9 p. M. 



Pressure of the Wind. For the measurement of the pressure of 

 the wind, a Lind's anemometer was furnished to each station. The 

 difficulty of obtaining accurate results with this little instrument 

 arises, partly, from the smallness of its indications, and, partly, 

 from the oscillations of the fluid in the tube ; the latter are so 

 considerable as to render the instrument of little value, except 

 in the hands of a patient and somewhat practised observer. After 

 some trial, accordingly, it was deemed advisable that the force of 

 the wind should be in all cases estimated, and that the use of Lind's 

 anemometer should be limited to that of furnishing a check upon 

 this estimation in the case of the stronger winds. 



The first thing to be determined, then, was the choice of a 

 scale of force. The scales in use are various : in one of them 

 there are four degrees of wind- force ; in another six ; and in a 

 third (the Admiralty scale) there are ticeke. The last of these 

 appears to be too minute for the ordinary powers of unaided esti- 

 mation, and the first not sufficiently so. The intermediate scale 

 (from to 6) was accordingly adopted ; and it appears to be 

 further recommended by the circumstances, 1, that it is the 

 subdivision most generally used on the Continent; and 2, that, 

 as its numbers represent the same degrees of wind-force with 

 the alternate numbers of the Admiralty scale, the latter are readily 



