Ennistrahull
ENNISTRAHULL, an island, in the parish of CLONCHA, barony of ENNISHOWEN, county of DONEGAL, and province of ULSTER, 8 miles (E.) from Malin Head, on the northern coast; the population is returned with the parish. It is situated in lat. 55° 26' 20", and lon. 7° 14' 10". Here is a lighthouse, built by the corporation for improving the port of Dublin, exhibiting a bright revolving light, which attains its greatest brilliancy every two minutes; the lantern is elevated 167 feet above the level of the sea at high water, and may be seen from all points 18 nautical miles in clear weather. About a quarter of a mile to the north is a rocky shoal, and further northward lie the Tarmore rocks, around which are always from 11 to 18 fathoms of water. In the channel between this island and the small isles called the Garvilans the stream of tide does not flow eastward until nearly five hours after high water, nor westward until five hours after low water, when its velocity is nearly four miles an hour.
Transcribed from A Topographical Dictionary of Ireland, 1840 by Samuel Lewis