og2 THE GEOLOGIST. 



depth of one foot in five years, and which, if compressed and solidified 

 into one-fourth part of that bulk," would, Mr. Moore reckoned, "be 

 as near an approach as can be made at the present day to the rate of 

 increase of bogs." 



The black bog contains much woody matter, and is believed to have 

 been formed on the site of ancient forests, great quantities of the 

 prostrate trunks of Scotch fir, oak, beech, alder, and yew being found 

 with their roots ni situ. The roots of the oaks are generally nearest the 

 margin of the bogs, resting on the clay or marl bottoms, while the 

 Scotch firs occur further towards the centre, and rest on several feet of 

 peat, thus showing that a considerable accumulation of that substance 

 must have taken place before they vegetated on it. A few of the trees 

 of those ancient forests, which once covered a large portion of Ireland, 

 still exist on the property of the Earl of Arran. 



The mountain-bog is often found at the elevation of 2,000 feet, and 

 in this variety, the grey moss, Racomitrium lamiginosum, supplies the 

 place of the Sphagnum. On passing the residence of the Earl of 

 Eelmore, we saw, for the first time, beautiful timber, and a well-kept 

 domain. Between Dublin and Enniskillen scarcely a tree is larger 

 than the thistles in the gardens and corn-fields, and a fine oak tree is as 

 great a novelty as a woman with shoes and stockings. The "Windermere 

 of Ireland, Lough Erne, separates at Ehniskillen into the upper and lower 

 lakes, the town being built upon an island connected by bridges with 

 the main land. The country around is undulating, with bold escarp- 

 ments of carboniferous limestone. The lower limestone forms the most 

 extensive series of surface-rock in Ireland; but in the northern counties 

 of Ecrmanagh, Cavan, Leitrim, and Eoscommon, it is, in some districts, \ 

 surmounted by the upper limestones of the series. The Calp series, 

 which separates the limestones, appears to be exceedingly variable asi 

 to thickness, as on the north-west coast of Leitrim it exceeds 1,700 

 feet, while in the county of Cavan it is not more than 400 feet thick, 

 and in the valley of the Barrow, at Carlow, is altogether absent ; the 

 upper limestone resting directly upon the black marble beds of the 

 lower. Enniskillen is admirably situated for much condensed geology- 

 At Lisbcllaw, south of Enniskillen, the traveller may commence witl^ 

 marvellous conglomerates of the Old Eed epoch ; and proceeding b} 

 Elorcncc Court and Culkengh Mountain to Killargas or Riverstown, be 

 twcen Loch Gill and Loch Anew, he may study every formation, froii 



