M‘Sweeny, on the Climate of Ireland. 195 
In the Annals of the Four Masters we have the following accounts : 
«« /Xtas mundi 1mpxxxir eruptio lacus con et lacus Techet anno hoc. 
« /Etas mundi impr eruptio novem fluminum. 
« ANtas mundi 11DLxxx1 eruptio novem lacuum. 
“« Doctor O’ Connor’s Version of the Four Masters.” 
If these accounts are to be credited, there can be no question as to the increase of 
humidity of the climate. If we suppose them to be true, we may attempt to explain 
the previous aridity by the theory of central heat. M. Cordier thinks that the thick- 
ness of the crust of the earth varies in different places, and he explains on the prin- 
ciple of central heat, the difference of climate in countries in the same latitude. We 
know from the fact of volcanoes, that internal fire in some places is not far distant 
from the surface of our earth, and that its operation sometimes is more active than it 
is at other times. 
We have only to suppose a cessation of activity in the operation of the internal 
heat in that part of the globe on which Ireland is situated, to account for the con- 
densation of vapours into rain, which previously might be dissolved by the heated air. 
Indeed there is one point which appears to corroborate this explanation, it is the ac- 
count in the Irish Annals of the formation of not only new rivers, but also of new 
lakes. 
An increased quantity of rain might cause old rivers to be flooded, or new rivers 
to be formed, but it would not cause the formation of new lakes, unless the level of 
the ground had been disturbed by its sinking in some places, or by its elevation in 
other parts from the operation of an earthquake, a visitation universally attributed to 
the agency of internal fire. 
This matter rests entirely on the authority of the old Irish records; where they 
assume more the shape of historical narrative, they give reason to believe that the 
climate in Ireland did not materially differ from the climate of the present day, and 
that remarkably wet, dry, cold, and mild seasons happened occasionally as at the pre- 
_ sent time. 
We have a very early account of a mild climate in Ireland, in the Annals of the 
Four Masters; we have also an early account of snow. “ A‘tas mundi mipcccLxvit 
Erat floribus estivis ornatus omnis campus in Hibernia tempore Fiachi.”— Annales 
IV. Magistrorum, Dr. O’ Connor’s Version. 
Keating tells us in his History of Ireland, that Fionnachta, the son of Ollamh 
Fodhla, obtained the name by which he was distinguished, on account of the quantity 
of snow that fell upon the island in his reign. We have in the Annals of the Four 
Masters, an account of a mild winter at an early period. 
« /Btas mundi m111cLx Regnante Conario—oberrabant armenta absque custode in 
Hibernia in ejus regimine propter abundantiam pacis et concordiz, non fuit tonitrale 
vel procellosum ejus regnum. Nam non fluxu afficiebat ventus asper, armenta a medio 
VOL. XVII. 2Y 
