[ 146 ] 



We often behold a fucceffion of years wherein winter feems 

 to have entirely loil its ufual horror, while the arbutus, the 

 laurel, the myrtle, and the rareft fpecies of evergreens, fpring 

 up with the vigour of indigenous plants, almoft emulating in 

 fize the trees of the foreft. Again, periods occur which fcnfibly 

 remind us of our vicinity to the polar ice, periods in which 

 the luxuriant foliage of our more tender plants is entirely 

 ■withered and deftroyed, and when even the mountain pine can 

 fcarcely maintain its hardy fhoots. 



Hence it is plain, that the fources of heat and cold in our 

 climate are variable in different years ; and it is a problem, 

 curious and interefting in its own nature, to determine what 

 may be the efFed on the general temperature of the kingdom, 

 whether it be an cncreafing or decreafing quantity ? whether it 

 be fubje<3: to periods of encrcafc and of diminution ? and whether 

 thefe periods, and the rate of their variations, be uniform or 

 irregular ? 



For this purpofe I have endeavoured, by fuch tneans as were 

 in my power, to afcertain the temperature of the foil of Ireland, 

 from its fouthern to its northern coaft, in the year 1788 and 

 part of 1787, the refults of which I here offer to the academy. 



But firft, it will be necefTary to ftatc the methods which 

 have been ufed to procure thefe refults, that fhould it be 

 thought worth while to repeat the experiments at any future 

 time, they may be made under circumftances as nearly fimilar 



as 



