Clare Island Survey — General Introduction and Narrative. 1 11 



intrusions), a great variety of scenery, and an extremely broken coast-line 

 with deep bays, bold headlands, and many outlying islands. 1 The highest 

 hill is Mweelrea (2688 feet), and summits of over 2000 feet are scattered widely 

 over the district, separated by great tracts of peat-bog and areas of cultivated 

 land. Heather is the prevailing formation over large areas, and the region 

 is singularly devoid of trees — the effect of exposure to the westerly winds 

 which sweep in from the Atlantic. The rivers of the area are small, on account 

 of the proximity of the watershed to the coast; lakelets, mostly occupying 

 rock-basins, are numerous. 



Prom Castlebar to the sea at Westport a tongue of limestone occupies the 

 continuation of the trough which forms Clew Bay. Elsewhere slates, sand- 

 stones, quartzites, mica-schists, &c, occupy the ground. The district has been 

 heavily glaciated, and in places cliffs of drift up to 100 feet in height, facing 

 the sea, attest the former wide extension of thick Glacial deposits. The lime- 

 stone-filled depression which runs down westward to Clew Bay is choked 

 with drift-mounds of drumlin type. As these dip below the sea they produce 

 the archipelago which fills the head of Clew Bay, and further seaward they 

 continue as a series of shoals. This interesting topography is shown in detail 

 on Plate VI of Part 7. The seaward edge of this archipelago has been 

 denuded by wave-action under the influence of westerly gales, and the islets 

 show every gradation from perfect whale-backed drumlins, through truncated 

 drumlins facing the sea with high drift-cliffs subtended by great boulder 

 beaches, to submerged banks of great stones. Plate III of Part 7 and 

 Plate II of the present part show some stages in this process of decay. 



As regards climate, thoroughly insular conditions prevail. The mean 

 temperature of the coldest month (January) is 42'8° F., and of the warmest 

 (August) 58 - 2° F. The mean annual rainfall is about 50 inches (much more 

 in certain places among the mountains), distributed over the unusually high 

 number of 266 rain-days. These figures refer to Blaeksod, at the north end of 

 the district, where there is a meteorological station. 



Clare Island itself lies across the entrance to Clew Bay, with channels 

 each of a minimum width of about three miles separating it from the 

 mainland on the north and the north-east. There is no need to describe the 

 topography of the island, since that is dealt with from various aspects in 

 several of the reports. In the illustrations accompanying the present notes 

 the appearance of the island from several directions is shown, and these 

 photographs convey a good idea of its topography. Towards the eastern end 



' A map of the district surrounding Clare Island is included in the present part, and others will he 

 found in Part 64 (Plate I), and Part 67 (Plate I). 



