X)n the rqualU Temperaime of the Irijh Clmme, 43 j 



They have altered the temperature of the ocean itfelf ; and thus have, as it were, muhi- 

 plied their changeful influence on the land ; adling there at once with new properties, as 

 well as with increafed quantity. 



The furface of water in a {late of tranquillity admits of greater variations of tempera- 

 ture than in a (late of agitation. It may become much hotter in fummer and colder in 

 winter when calm than when didurbed ; for the particles at the furface, when heated or 

 eoolcii, do not immediately give place to others nearer the bottom ; the procefs of com- 

 mixture, in a tranquil (late, is gradual, and the tranfmiffion of change fomewhat re- 

 femblcs the flow and retarded progrefs that takes place on the land. Agitation always 

 counteradls this gradual procefs; a rapid commixture of the particles produces a quick. 

 aflTmiilation of temperature throughout the whole niafs, and, thus taking away all partial 

 excefs, reduces the whole toward a medium (late of uniformity. 



Thus, fummer tempefts always tend to dimlnifli the fuperficial heat of an ocean over 

 •which they ru(h ; while winter blafls, agitating the waters at confiderable depths, refift' 

 the natural cold of the feafon by a fupply of relatively warm particles, which arife from 

 tlie bottom toward the furface. 



That the Atlantic ocean, the. vaft and potent arbiter of our feafons, has fufFered un- 

 ufual agitation of late years, feems evident from the natural phenomena recorded in the be- 

 ginning of this Memoir. The trees and fands of our iflaiid bear teflimony to the dorms 

 which fweep along its furface ; and the tides come to us as frequent and unerring mef- 

 fengers of the tumultuous and agitated (late of its billows attendant on their furious "fcareer. 



From this perturbed abyfs of waters has arifen an unceafing influence, equally potent 

 to check the ardour of the fummer folar beams,, or to relax the (hackles of a. northern 

 winter. By this prevailing influence, fummer has been rendered impotent to raife and 

 ripen many of our crops j.and the farmer, taught by, neceffity, learns now to hand them 

 over ready grown,. and prepared for the maturity of fummer under the mild temperature 

 of. an Atlantic winter. Hence too the gardener has, of late years, been compelled to call 

 in the aid of artificial heat to forward the peach, the ne£larine, the grape, and every othef 

 fpecies of delicate fruit to perfe6lion. 



Hence premiums now vainly attempt the growth of hemp, which formerly peafants, in 

 the mod northern counties of Ireland, cultivated without reward around their cabins for 

 domedic ufe. And hence the ancient apiaries of our ifland, once fo celebrated, and 

 guarded with fuch fpccial and minute attention by the Brchon laws *, are now extinft ; 

 and honey, from being a common article of popular confumption, has becoine a rare 

 luxury, or an expenfive medicine. 



Winter has likewife felt the general influence of this Atlantic temperature; our grafles 

 fcarcely droop beneath the frofls ; wheat and oats vegetate in the open fields during the 

 very folftice itfelf; myrtles and laurels, in fheltered fituations, brave the feverity of winter ; 

 the Foyle, and other large rivers of the northern province, frequently fubjeft to the icy 

 chains of former ages, now run in uninterrupted freedom f' 



* See Colleftanea dc Reb. Hib. Tranfl, Brehon Laws. 



•|-_ Fifty years have clapfed fince the river Foyle has been tffeQually frozen over at Derry. It is alfo ob- 

 ferved that the river Thames, in Britain, is lefs frequently frozen of late years than formerly. See Aichaeo- 

 logia Britannica, vol. iii. p. 55. . 



