THE CLIMATE OF IRELAND. 37 



these may be briefly reviewed here in so far as they affect Ireland, under 

 the following heads, viz. : — 



Temperature. 



Latitude. 



The Gulf Stream. 



Configuration of the ground. 



Aspect. 



Relation of temperatures of air and soil. 



xA.erial currents. 



Atmospheric moisture. 



Vapour condensation. 



Cloud, fog, dew, mist, rain. 



Wet and dry winds. 



Rainfall. 



Weather prognostication. 



TEMPERATURE. 



Every reader is likely to be aware of the manner in which the tempera- 

 ture of Ireland is affected by its position as regards 

 latitude. It will guard against exaggerated estimates 

 Latitude, ^^ ^^ extent to which the local temperatures of the 



north and south of the country differ, to say that while 

 3,700 miles intervene between the Frigid and Torrid Zones — between the 

 regions of arctic cold and tropical heat — the length of this island is only 

 270 miles, or one fourteenth of the former distance. 



The temperatures of north and south, in regard to latitude, are of course 

 the direct results of the sun's heating power ; but though this be recognised, 

 the amounts cannot be known by observation independently of the effects 

 of other heat-applying agencies — the Gulf Stream, warm air currents, 

 vapour condensation, etc. Observed temperatures involve the existence 

 and co-operation of all these, and show about 4° F. for the January mean ; 

 2° 5 F. for August ; and 3°. 3 F. for the year, in favour of the south. 



The Gulf Stream is a potent agency in influencing temperature. This 

 vast body of water, issuing from the Gulf of Mexico, 



T^v» r If cf flows north-eastward past Florida, into the North 



ine uuii stream. Atlantic Ocean. It continues its course across the 

 ocean, with an average temperature of 65 F.,* dividing 

 into two branches, a north-easterly, which flows past the British Isles, and 

 an eastward branch flowing towards the coasts of France. Parts of both 

 blanches strike the S.W. coast of Ireland and flow northward ; and part of 

 the eastward branch, turning northward in the Bay of Biscay, flows up to the 

 English and St. George's Channels, and towards the Irish coast. The heat- 

 ing effect upon the British Isles is such that the mean winter temperature of 

 Ireland is 20° F. higher than that of places on the same parallels of latitude 

 m America and West Russia. The body of water also being so great, is 

 productive of uniformity in temperature ; so much so that the mean summer 

 temperature of Ireland is some 5° F. to 10° F. lower than that of east 

 Prussia. The amount of caloric which the Gulf Stream possesses, and can 



* " Meteorology, Practical and Applied," (p. 314), by Dr. J. W. Moore,, iiow Sir J. W. Moore. 



