82 Proceedings of the Royal Irish Academy. 



XI. — Eepoet ois THE Botany of the Island oe RiTHLiN, Cotjntt of 

 ANTEiir. By SAiitJEL A. Stewart, FeUow of the Botanical Society 

 of Edinburgh, Curator of the Collections in the Museum of the 

 Belfast Natural History and Philosophical Society. 



[Read, January 14, 1884.] 



Eathlin Island is situated at the northern extremity of the Antrim 

 coast, in lat. 55° 20' north, and 6° 15' west longitude. It has an area 

 of 3200 acres, and is, consequently, the largest island on the coasts of 

 the jSTorth of Ireland. Landing on Eathlin, the visitor finds himself 

 on a belt of rocky, mountainous land, ranging from about half a mile 

 to over one mile in breadth, and extending for a distance of about five 

 miles in a direction which is almost exactly east and west. At the 

 lighthouse,, which is located at the extreme north-east, the coast 

 bends at a sharp angle, and runs thence southwards for over three 

 miles, terminating, in this direction, at Rue Point, in TJshet. Fair- 

 head, on the mainland, is separated from the island by nearly four 

 miles of a turbulent sound, through which rapid tidal currents run 

 with immense force, rendering the passage impossible in a high 

 wind. As stormy weather is here of frequent occurrence, the com- 

 muiucation with the Antrim coast is often cut off for longer or 

 shorter periods. On the occasion of my third visit, which was in 

 August, there were three days in succession during which the boat 

 could not leave. The main portion of the island lies seven to eight 

 miles off the Antrim coast ; while the nearest point in Scotland 

 is the Mull of Cantyre, distant about fourteen miles to the east. Islay 

 is some twenty miles to the north. 



The physical aspect of Rathlin is not inviting. 'Eo flowing out- 

 lines of softly-swelling landscapes meet the eye, but bare, rugged 

 crags, which are neither relieved by sylvan glades nor running water. 

 The rocky foundation has only a very slight covering of soil to absorb 

 excess of moisture ; and numerous depressions amongst the crags are 

 filled with water, and form lakelets, which are sometimes of consider- 

 able depth. The largest sheet of water is the lake at Ushet, which 

 has an area of over thirty acres. Cleggan Lough, to the north-west, 

 is a deep basin, enclosed in an amphitheatre of low hills. Its area is 

 about ten acres. There are, in addition, many reedy marshes, assum- 

 ing the aspect of lakes in a wet season, but which, nevertheless, dis- 

 appear, or become reduced to very small dimensions in dry weather. 



The land surface rises steadily fi'om Ushet at the south and east to 

 the Bull at the west end of the island ; and as if to compensate for the 

 unprepossessing interior, the western sea-cliffs are magnificent. The 

 rocks on the south side are mainly of hard chalk, precisely similar to 



