Slate Islands, Scotland
[5] W. H. Murray in The Companion Guide to the West Highlands of Scotland goes so far as to say: "Seil and Luing, Shuna, Torsa, Belnahua and many others are collectively known as the Slate Islands.
[8] The neighbouring islands to the west, Lunga and Eilean Dubh Mòr, are constituted of quartzite, "Scarba conglomerate" and other rocks that lack a commercial value.
[9][10] It therefore seems reasonable to conclude that this collective noun includes the commercially quarried Easdale, Belnahua, Luing and Seil, plus their larger and relatively recently inhabited close neighbours of Shuna and Torsa with the "many others" being the smaller uninhabited islands and skerries in their immediate vicinity.
There are numerous NW-SE aligned basalt and microgabbro dykes which form a part of the ‘Mull Swarm’ which is of early Palaeogene age.
Raised marine deposits of sand and gravel occur widely around the margins of some of the islands, a legacy of late Quaternary changes in relative sea-level.
[33][34] From about the 6th to the 8th century AD the Cenél Loairn kindred controlled what is today known as Lorn, which region includes the Slate Islands, in the then kingdom of Dalriada.
[36] By the late 8th century the area was a zone of conflict between the Celtic rulers of mainland Argyll[Note 3] and the newly arrived Norse settlers.
[38] It has been suggested that Seil may be the Innisibsolian referred to in the Chronicle of the Kings of Alba, which records a victory by the Scots over a Viking force during the time of Donald II.
Two years later Bruce led three thousand veterans into Argyll against the MacDougalls and at the Battle of the Pass of Brander they were defeated and King Robert held most of their lands to be forfeit, including all their island possessions save for Kerrera.
The failure of King James VII to regain the thrones of England, Ireland and Scotland led to the MacDougalls losing much of their land to the Duke of Argyll.
From the late 17th century the Dukes of Argyll began to lease land on a competitive basis rather than as a means of strengthening the welfare of their senior clansmen.
Peak production was reached in the 1860s at 9 million slates per annum, with export destinations including England, Nova Scotia, the West Indies, the US, Norway and New Zealand.
In the early morning of the 22nd November a severe gale from the south-west wind and an exceptionally high tide flooded the quarries on Easdale and at Eilean-a-beithich "a large rocky buttress which supported a sea wall gave way under the excessive pressure of water".
Changes in demand - clay tiles were rapidly replacing slate as the roofing material of choice - led to commercial production ceasing by 1911 on Seil and in 1914 on Belnahua.
[61] The Firth of Lorn is the seaway used by vessels going to and from Oban and Fort William from points south and the seas around the Slate Islands contain the sites of various shipwrecks.
Encountering a storm, she headed for the Firth of Lorn seeking shelter although the light load meant that the propeller was ineffective in the high seas.
[62] There is an extensive drying reef to the north of Belnahua[19] and at 10pm that night the Helēna Faulbaums struck it broadside and foundered, sinking within ten minutes[62] with the loss of 15 lives including two 18-year-old boys.
