224 
Proceedings of the Royal Irish Academy. 
caused streams to dry up. Thus Rio Janeiro, as Gardner states, had 
its climate changed from wet to dry, and the Brazilian Government 
was forced to forbid the felling of the trees on the Corcovado range, 
through a new fear of drought. The growth of bog assisted 
largely in lake obliteration. Subterranean channels must also be 
counted. Moorlough, near Strabane, I have seen emptying itself into 
a subterranean channel, until the aperture was banked up by the mill- 
owners. This channel might have been the precursor of an outbreak, 
by which the gravelly bank would have been swept away, and a little 
glen or ravine formed. 
As to the migrations" which have excited wonder and some 
doubt, they are quite in conformity with the well-attested facts of 
recent times. Thus, they find a parallel in the outbreak of the 
lake near Martigny, in the Vallais, the escaping torrent of which 
traversed the forty-five miles to the Lake of Geneva in five hours, 
destroying all in its course. Another instance occurred in 1810, in 
Vermont, U. S., when a lake, a mile long and three-quarters of a mile 
wide, broke its barrier, ploughed a vast furrow into a lower lake, 
burst bounds again, so that the waters of both lakes excavated a 
channel thirty feet wide, and from twenty to sixty feet deep, through 
a valley five miles in length. The confirmation thus given in many 
points to the Irish Annals by the facts of geology, lends an additional 
interest to their curious chronicles of the eruptions of rivers and lakes 
in pre-Christian times. Such occurrences would show that Ireland 
was, of old, remarkably ■ subject to earthquakes. And it increases the 
reasons for crediting the chronicles to learn that a vivid tradition is 
still preserved in Sligo of an earthquake which, the Annals say, 
resulted, so late as a. d. 1490, in the production of Meemlough (i. e. 
the eruption lake),f and in the destruction of a hundred men and 
much cattle. It is obvious that the confirmation of the chronicles and 
the physical facts pointed out may prove of importance in defining 
or limiting the antiquity of animal remains or of relics of human 
existence. It is conceivable, for instance, that objects found deeply 
buried in detritus, and regarded as extremely ancient, might owe their 
interment (at a comparatively recent period) to the furrow of a burst 
lake or the deposit of a river which had changed its channel. 
* The public press mentions the disappearance, in the present year, of a large lake 
in Lithuania, district of Telchef ; it measured eight versts by five, and its fishery was 
■worth 15,000 roubles annually. During a calm, its waters rose and seemed as if agitated 
by a tempest. A sulphurous smell was perceived, and the lake became covered with 
dead fish. Then the waters began to sink (the sulphurous odours increasing), until the 
lake-bed was almost dry. 
f Of. " In England, in 1755, a pond in the town of Luton, in Bedfordshire, in 
which there had been but little water for some weeks, suddenly filled, and a copious 
sediment was thrown up from the bottom, at the precise time of the earthquake at 
Lisbon, the water continuing too verflow for some hours." — Griffith's " Bog Keports," 
p. 176 ; 1810. The Irish Annals say that, at Meemlough, there were " m.any putrid fish 
thrown up," a statement which, bringing the occurrence to a close resemblance with 
tliat in Telchef, may indicate the previous existence of a pond or pool. 
