Editing Seil (section)

===Slate quarrying===
In 1730 Colin Campbell of Carwhin was appointed as the Captain of Ardmaddy and tasked with exploiting the area's natural resources. At this time Easdale slate had been used from as early as the 12th century using seasonal labour from the Ardmaddy estate.{{sfnp|Withall|2013|p=5}} In 1745 Campbell created the Easdale Marble and Slate Company in order to place  extractions from the area on a more commercial basis.{{sfnp|Withall|2013|p=6}} At that point Easdale was producing 1 million slates per annum; when [[Thomas Pennant]] visited two years later production had increased by 250% and as further quarries were opened this further increased the company's production to 5 million per annum by 1800.{{sfnp|Withall|2013|p=7}}

The little island of [[Eilean-a-beithich]] between Seil and Easdale was quarried down to a depth of {{cvt|80|m}} and other slate quarries were opened on Luing and at Balvicar. Railway lines were laid to take the rock from the quarries to nearby harbours. 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. The [[John Campbell, 6th Earl of Breadalbane|6th Earl of Breadalbane]] had less interest in the industry than his predecessors although during the time of the [[Gavin Campbell, 1st Marquess of Breadalbane|7th Earl]] a new quarry was opened at Ardencaple.{{sfnp|Withall|2013|pp=7-9}} However, disaster struck in 1881. In the early morning of 22 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".<ref name=electric>[http://www.electricscotland.com/books/netherlorn2.htm "Netherlorn and its Neighbourhood:Chapter II - Easdale"] Electric Scotland Retrieved 18 March 2012.</ref><ref name=southern>[http://www.southernhebrides.com/slate-islands.html "Slate Islands - The Islands that Roofed the World"] Southernhebrides.com. Retrieved 14 November 2009.</ref>  Eilean-a-beithich was never re-opened although production did continue at Easdale, Luing and Balvicar. Changes in demand - clay tiles were rapidly replacing slate as the roofing material of choice - led to commercial production ceasing by 1911. Balvicar quarry re-opened from the late 1940s until the early 1960s{{sfnp|Withall|2013|pp=9-10}} but slate is no longer mined anywhere in the Slate Islands.