Dubh Artach (; ) is a remote skerry of basalt rock off the west coast of Scotland lying west of Colonsay and south-west of the Ross of Mull.
A lighthouse designed by Thomas Stevenson with a tower height of was erected between 1867 and 1872 with a shore station constructed on the isle of Erraid. The rock is subject to extraordinary sea conditions with waves of or more being encountered by the keepers. Despite these adverse conditions several men served the light for lengthy periods until it was automated in 1971. Dubh Artach is the official name of the lighthouse, although the skerry itself is also known as Dhu Heartach. Various interpretations have been provided for the original meaning of the Gaelic name, of which "The Black Rock" is the most likely.
Geology
In pre-historic times Dhu Heartach was covered by the ice sheets that spread from Scotland out into the Atlantic Ocean beyond the Outer Hebrides. After the last retreat of the ice around 20,000 years ago, sea levels were up to lower than at present. Although the isostatic rise of land makes estimating post-glacial coastlines a complex task, circa 14,000 BP it is likely that Dubh Heartach was at the western edge of a large land bridge linking what is now the island of Ireland to Scotland. This land mass included the islands of Jura and Islay and was probably connected to the mainland of Scotland by an isthmus near Loch Craignish, south of Oban.
Steadily rising sea levels would then have slowly isolated and finally all but submerged Dhu Heartach, which today is a rounded, dark green mass of basaltic rock called augite, which is long and wide, and which rises to above sea level. Submarine surveys indicate that the rock is at the eastern end of a valley stretching into the Atlantic, which may "account for the seemingly abnormal seas to which the tower is subjected". It is an isolated outpost of the Inner Hebrides archipelago. The author Robert Louis Stevenson wrote:
An ugly reef is this of the Dhu Heartach; no pleasant assemblage of shelves, and pools, and creeks, about which a child might play for a whole summer without weariness, like the Bell Rock or the Skerryvore, but one oval nodule of black-trap, sparsely bedabbled with an inconspicuous fucus, and alive in every crevice with a dingy insect between a slater and a bug. No other life was there but of sea-birds, and of the sea itself, that here ran like a mill-race, and growled about the outer reef for ever, and ever and again, in the calmest weather, roared and spouted on the rock itself.
Meaning of the name
The translation of Dubh Artach is "The Black Rock", artach being a now obsolete Gaelic word for a rock or rocky ground both in Scottish Gaelic and in Irish. The variation between the anglicised forms Dubh Artach and Dhu Heartach is a simple case of false splitting where the final [h] of [t̪uh arˠʃt̪əx] in pronunciation seemingly is part of the following word, suggesting *hartach or heartach to the untrained ear.
Stevenson believed that 'black and dismal' was a translation of the name, noting that "as usual, in Gaelic, it is not the only one." Adamnan in his 7th-century Life of St Columba poetically calls the rock An Dubh Iar-stac, "The Black Stack of the West". Watson (1926) suggests the root is Old Irish hirt meaning "death", (which he also believes occurs in Hirta, the main island of the St Kilda archipelago), and offers am Duibh-hirteach, meaning "the black deadly one". The skerry was also known as St. John's Rock prior to the construction of the lighthouse.
Planning and construction of the lighthouse
Between 1800 and 1854 thirty ships were wrecked on the reef; however, the requirement for a lighthouse was not only to warn seafarers away from Dhu Heartach itself, but also to guide them past the fearsome Torran Rocks, which lie between the Ross of Mull and Colonsay. Originally it was considered to be an impossible site for a light, but the loss of the steamer Bussorah with all thirty-three hands on her maiden voyage in 1863 and of an astonishing 24 vessels in the area in a storm on 30–31 December 1865 encouraged positive action under pressure from insurers Lloyd's of London and a Captain Bedford of the Admiralty. The engineering work was supervised by the famous Stevenson family of engineers, the brothers Thomas (father of Robert Louis) and David commencing work in 1866. Thomas noted that "it would be a work of no ordinary magnitude".