The Rev. H. Lloyd on the Meteorology of Ireland. 475 



2. The amount of raiu is greatly dependent on the proximity of a mountain 

 chain or group, being always considerable in such neighbourhood, unless the 

 station be to the east or north-east of the same. Thus, of the places oUeast rain, 

 Portarlington lies to the north-east of Slieve-bloom ; Killough, to the north-east 

 of the Mourne range ; Dublin, to the north-east of the Dublin and Wicklow 

 range ; while, on the other hand, the places oi greatest rain, — Cahirciveen, West- 

 port, and Castletownsend — are in the vicinity of high mountains, but on a dif- 

 ferent side. 



These facts are easily explained. The prevailing wind blows from the S. W., 

 and reaches this island loaded with the vapour of the gulf-stream. This vapour 

 is condensed and precipitated in rain, when it first meets the colder air over 

 the land, namely, on the westei'n and south-western shores. But the principal 

 condensing centres are the mountains, in the neighbourhood of which, conse- 

 quently, the precipitation is more abundant, and especially on their western and 

 south-western sides. And the same circumstance which causes the greater 

 precipitation at these points must also protect the region over which the wind 

 next passes (the north-east), the air being thus deprived of a large portion of 

 its vapour before arriving there. 



Tables. 



The following Tables contain the portions of the individual observations, 

 the results of which are referred to in pages 4.50—469. 



Table xxxiii. contains the selected observations on days of storm, or of 

 marked cyclonic movement. It comprises the direction and force of the wind, the 

 pressure, temperature, and amount of cloud, at the time of observation ; as also 

 the greatest and least temperatures, and the quantity of rain fallen, in the pre- 

 ceding twenty-four hours. The pressures are, for comparison, reduced to the 

 mean sea-level ; the numbers in the Table are the excesses above 28 inches. 

 The force of the wind is expressed in terms of the scale (0 — 6). 



Table xxxiv. contains the hourly observations on the term-days, March 21, 

 22, and June 21, 22, at Portrush, Armagh, Markree, Courtown, Dunmore, and 

 Cahirciveen. The velocity of the wind at Portrush, Armagh, Markree, and 

 Courtown, was observed by means of Eobinson's anemometer; it is expressed 

 in feet per second. 



VOL. xxn. 3 Q 



