XXVI IXTROBUCTION. 



CLIMATE — As it is well known that the flora of a disti-ict is largely- 

 affected by the meteorological conditions which prevail, it becomes 

 necessary to offer some general remarks on this head, although there 

 seems to be Kttle that is peculiar in the meteorology of the northeast of 

 Ireland. 



The means of annual temperature, hereafter stated, range from 48*5 to 

 48-8 degi-ees of P'ahrenheit. This is less than the average for the 

 remainder of Ireland by nearly one degree, but if we exclude from this 

 comparison a limited area near the south and southwest coasts, the 

 difference will be found to be very slight. 



The average yeaiiy temperature of the north of Ireland corresponds 

 very nearly to that 'of the north of England, but in the former the 

 thermometrical range is smaller. Our more clouded skies moderate the 

 winter frosts as well as the summer heats. In the very limited bounds 

 of this district the local range can of course be only slight, but the greater 

 humidity, and more equable temperature of the sea-coast, find their 

 botanical expression in the increased variety of plants to be met with 

 there. 



The opinion loosely formed, and freely expressed by many visitors, to the 

 effect that Belfast and distiict is a very wet region is not borne out by exact 

 observation. This popular fancy is, no doubt, due to the many wet days in 

 which the actual volume of rain is slight. The Scottish M'eteorological 

 Society having recently collated the rainfall returns of the British Islands 

 has displayed the results in a general way by means of coloured maps. 

 An inspection of these maps shows that the northeast of Ireland lies in 

 the region of least rainfall in this island. An annual rainfall of 30 to 40 

 inches is indicated on the maps in question by dark red shading, and this 

 colour covers almost the entire east coast, and a great portion of the 

 centre of the island. In the northeast the uniformity of colouring is 

 broken by a small strip in south Down, which forms part of a greater 

 rainfall — over 40 inches. A similar rainfall, coloured light blue on the 

 maps, prevails in Donegal, and extending to the east, penetrates as a 

 narrow wedge to the centre of the county of Antrim. 



