

TIREY. GENERAL DESCRIPTION. 23 



island as they do over the sea, materially disturbing the 

 operations of agriculture by dispersing the seed together 

 with the loose and dry soil; and often breaking down 

 the crops both of corn and potatoes when these have 

 attained to their full growth. 



The southern half of the island is almost an uninter- 

 rupted plain, with a few scattered rocky elevations; but 

 towards the northern end the rocks become numerous, 

 and, as in lona, at length occupy the greater part of 

 the surface, impeding the cultivation of the soil, and 

 condemning it to perpetual pasturage. At the northern 

 extremity there are considerable accumulations of blown 

 sand. 



Notwithstanding the general flatness of the surface, 

 Tirey presents three distinct hills near its southern ex- 

 tremity, the highest of which scarcely attains the elevation 

 of 400 feet. A few low hills towards the northern end 

 range from 30 to 60, and would scarcely be noticed in a 

 country less flat than this. It contains two small lakes, 

 one at its southern and the other at its western side, be- 

 sides some smaller pools ; but presents no stream or 

 running water except that w r hich is discharged from one 

 of the lakes and applied to the use of a mill. This want 

 of streams arises from the flatness of the land, as, although 

 the climate is far from wet when compared with the 

 neighbouring high lands, there seldom passes a week in 

 any season of the year without rain. To compensate this 

 defect, water is procured by digging, within a few feet 

 of the surface ; and in various parts of the island where 

 there is a w r ant of drainage it is also found producing 

 marshy spots. 



The soil is in general light, consisting of sand mixed 

 with peat earth ; but the island is remarked for its fertility, 

 forming, in proportion to its extent, one of the most 

 valuable tracts of land in these seas. This fertility is 

 partly the result of the calcareous nature of the sand, 

 which contains, together with quartz, a large proportion 





