440 



The Eev. H. Lloyd on the Meteorology of Ireland. 



Table XVII. Monthly Means of Barometric Pressure ior the Four Groups of 



Stations. 



North-east, . . 



Kortli-west, . . 



South-east, . . 



South-west, . . 



JaB. 



Feb. 



Mar. April. 



May, 



l-5752005'l-732;i-925 2-111 

 1-475 1-970' 1-715 1-908,2-120 



1-600 2-007:1-748 

 1 5561-97l|l-764 



1-900,2-104 

 1-879|2-106 



June, 



July, 



Aug, 



Sept, 



Oct, 



Nov, Dec, 



1 -995 1 -879 2-035 2-226! 1 -8 17 2-040 2-201 

 l-992'l-897'2-012 2-200 1-80112-095 2-186 

 2-016,l-888'-2-048'2-2-26|l -8621-2-063 2-240 

 2-012:1-902 2-028:2-206jl-879j2-146 2-233 



Year, 



1-962 

 1-948 

 1-975 

 1-974 



The phenomena of the distribution of pressure are very clearly shown in 

 the foregoing Table, It will be seen from it that, on the average of the entire 

 year, there is an excess of pressure in the south of the island, and a defect in the 

 north, the minimum being at the north-wester?! extremity. This excess of 

 pressure in the south is likewise shown in the means for the seasons of summer, 

 autumn, and winter, respectively ; and the cause of it will, I think, hereafter 

 appear upon the discussion of the phenomena of storms. In the separate months, 

 the points of greatest and least pressure vary somewhat irregularly ; but they 

 are, in almost every month, at opposite extremities of the island. Thus, in 

 January, the maximum pressure is in the south-east, and the jninimum in the 

 north-west; and so for the others. This circumstance is what should have been 

 expected a priori ; and it affords satisfactory evidence of the general accuracy 

 of the results themselves. 



Direction and Force of the Wind, 



Direction of Wind. — The direction of the wind was observed, at most of 

 the stations, by means of the ordinary wind-vane. Much care was, however, 

 taken, not only in placing these instruments truly in azimuth, but also in se- 

 lecting positions for them which seemed least exposed to eddies or other local 

 irregularities. At Armagh and Dublin the direction of the wind was recorded 

 continuously, by means of self-registering anemometers. 



The following Tables give the number of times, out of 100, in which the 

 wind blew from each of the eight points at the several stations ; Tables xviu. and 

 XIX, containing the results for the summer and winter half-years, respectivelj', 



