Of the Bogs in Ireland. 445 



in thickness, and which almost universally covers the sur- 

 face of the gravel, by obstructing the course of the waters 

 in a country having naturally but little fall, may, by creating 

 a general stagnation in them, and thereby forming extensive 

 shallow lakes, have caused the growth of the Sphagnum 

 paluslre*, and other aquatic mosses and plants, of which 

 the mass of our bogs is composed. 



" This island, though separated from the southern range 

 of hills by a low boggy valley, may on a general view be 

 considered as a continuation of that range. 



te Perhaps a short geological description of this ridge, 

 'which, on account of its height and steepness, forms the 

 most prominent and interesting feature in the county,) 

 though apparently foreign to the general object of this re- 

 port, may (by preventing ignorant people from search- 

 ing for limestone and other manures where they do not 

 exist) be considered as an useful and necessary appendage. 



u Near Ballyteague Castle, in the northern edge of the 

 Island of Allen, stratified limestone makes its appearance 

 at the surface, dipping 20 degrees east of south, at an angle 

 of 5 degrees from the horizon. The stone is principally 

 used for building, as on account of its containing a large 

 proportion (according to my analysis 15 per cent.) of silex, 

 it requires much fuel to burn it into lime. 



" The next rock visible crops out about two miles to the 

 •outhward of Ballyteague, at the base of the Hill of Allen 

 near the village called the Leap of Allen, the intermediate 

 country being covered by hills of limestone gravel ; it is a 

 species of conglomerate, composed of rounded quartz peb- 

 bles, varying in size from minute sand to six inches in dia- 

 meter, connected together by a red iron-shot, argillaceous 

 cement ; then beds of a deep brick red slate ; clav much 

 interspersed with mica is found interstratified with the 

 conglomerate : the dip is 30 degrees east of south at an 

 angle of 7 degrees from the horizon. Southward of this 

 quarry, rises the Hill of Allen, a very steep conical hill 

 about 300 feet high (reckoning from its base) ; it is com- 

 posed of an irregular unstratified mass of fine-grained green- 

 stone, the crystal of hornblende and feldspar being very 

 minute ; transparent calcareous spar is frequently observable 

 in the mass, rarely large crystals of feldspar are found in- 

 terspersed ; the rock on approaching the summit of the hill 

 becomes more crystalline, detached masses of beautiful por- 

 phyretic greenstone thickly studded with large crystals of 



* Bog Mom. 



fold- 



