M‘Sweeny, on the Climate of Ireland. 197 
In the year 821, which, according to the computation in these Annals, agrees with 
the year 822 of the Christian era, it is recorded that the sea was frozen ; but we find 
that in the year 822, the principal rivers of Europe, such as the Danube, the Elbe, 
and the Seine, were frozen so hard as to bear heavy waggons for a month. It may 
be boldly asserted, that Ireland, from its insular situation, suffered less by cold that 
year than the continent of Europe. But it is to be believed, that the state of the 
surface of the island, unimproved as it was, in comparison with its present state, must 
have greatly aggravated the cold of a severe winter, when it happened from a general 
cause. Swamps, and bogs, and pools, are soon frozen ; at the present, draining, cul- 
tivation, and reclaiming, have made great progress. 
By the aid of chemistry it is easy to prove that Ireland never could have just 
claims to the appellation of Glacialis Ierne : 
“ Tlla ego sum Graiis olim Glacialis Ierne 
Dicta, et Jasonie puppis bene cognita nautis.” 
The water of the ocean mitigates cold in this way ; the upper particles of the 
water, when cooled by the air, sink, and allow a warmer stratum of water to come in 
contact with the atmosphere ; this process goes on, until the water, by long exposure 
to the cold, acquires its maximum of density. 
The vast body of water of the Atlantic must, therefore, at all times, have rendered 
the winters in Ireland, mild, when compared with the winters in other countries. 
The appellation of “ Glacialis lerne,” might have arisen on account of navigators 
from the Mediterranean, having been in the island during a severe winter, in for- 
mer times. ‘The crew of a vessel from a warm climate in the Mediterranean, would 
be apt now to form an erroneous opinion ae the climate of Ireland, if they had 
been here in the winter of 1812. 
The island described by Diodorus Siculus, is supposed by some to be Ireland, from 
the description ; the soil fruitful, the country diversified with mountain and plain, 
watered by navigable rivers, abounding in woods, and orchards, and all the island 
watered by streams, and the summer season fitted for pleasure and amusement— 
Diod. Sic. vers. Wesseling, t. 1, p. 344. 
Whether this island was the one described by him, or not, is a matter of surmise ; how- 
eyer, this description may be received as a true one of Ireland, at the present day. The 
island inhabited by the Hyperborei, he tells us, was so fruitful, and the climate so tem- 
perate, that they mowed twice in the year.—Diod. Sic. t. 1, p. 158. 
Festus Avienus, writing of that which was called the sacred island, says : 
“Hee inter undas, multum cespitem jacit 
Eamque late, gens Hibernorum colit 
Propinqua, rursus, insula Albionum patet.’”—De Oris Marit. 
The expression ‘‘ multum cespitem” may be received now, as applicable to Ireland, in 
reference to a peaty soil, or to its grassy sward, 
