10 SHRINKAGE FISSURES RECENT DEPOSITS. 



proceedings occur, especially in mountainous bogs. 

 One worthy of record was observed north-west of 

 Koundstone, County Galway. Here is a flat bog 

 bounding a lake ; and some years ago, during a very 

 dry summer, a crack opened in the former ; this was 

 taken possession of by the water of the lake, which 

 deepened and slightly widened it, thus forming a 

 connection between the upper lake and Lough-na- 

 Sooderry, so that now the surface of the water in the 

 former is always four feet lower than it used to be. 



Cracks also form in flat bogs, and at different times 

 they have indirectly caused large tracts of the Irish 

 bogs to move. One of these movements occurred about 

 fifty years ago, near Clara, King's County, under the 

 following circumstances : The drought of a very 

 dry summer not only opened fissures in the bog, but 

 also, as it would appear, in a great measure cracked 

 it away from the subjacent marl and gravel. Such a 

 process can be seen on a small scale on any boggy 

 mountain after a -few weeks of very hot sun. The 

 water seems to have afterwards got under the peat, 

 and when the inhabitants of the country cut their 

 turf, they severed the marginal connection between the 

 peat and the underlying strata, and the whole bog 

 moved away. The phenomena was thus described by 

 an eye-witness : " I remember the bog moving. It 

 is about forty years ago, the year before the king 

 [George IV.] came to the Curragh. It was a very 



