EARTH'S SURFACE METEORIC ABRASION. 81 



to act evenly on all parts of a cliff, for as fast as the 

 denudation goes on, the .debris is blown away often 

 over the top of the cliff, therefore a perpendicular 

 cliff denuded by wind ought generally to retain its 

 vertical character. 



In Ireland, wind seems to preserve, in a great 

 measure, the vertical fronts of the huge step-like 

 cliffs or terraces, for which the barony of Burren, 

 Co. Clare, is remarkable. Its effect, however, would 

 be small but for the help received from heat, cold, 

 and rain, they disintegrating the .rocks and forming a 

 material easily carried away by wind. Chemical action 

 must also materially assist by dissolving away large 

 portions of the rock (limestone). The rain in this 

 district acts peculiarly, as most, if not all, of the 

 matter it removes is carried off in solution, little or 

 no accumulation of surface soil taking place, while the 

 joints and cracks remain as open fissures. The wind 

 blowing through these fissures tends to carry all the 

 insoluble residue away ; but it cannot always accom- 

 plish this, as, during the summer, plants grow in 

 many of the cracks, and their foliage prevents the 

 wind acting. 



Wind work can be studied in soft sandstone cliffs, 

 such as those of New Red Sandstone age on the coast 

 of Devonshire, where, after a gale, the direction of the 

 wind can be traced on the face of the cliffs, it form- 

 ing a miniature " crag and tail " (if it may be so 



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