Object of the Month: August 2016

Lime Quarrying and Burning

It is easy to be misled by the appearance of the Lismore limestone.  Although much greyer than many commercially-exploited  limestones, it is a high-quality source of calcium carbonate (around 90%), and its suitability for burning to produce lime for building and agriculture has been known for centuries.  Before the development of large-scale kilns, lime would have been burnt at a smaller-scale – for example in the clamp kiln that survives at Park, next to an area of coppiced hazel that would have provided fuel.

The Park clamp kiln (the horseshoe shaped structure) with a pile of broken stone (right) and a small quarry face

The Park clamp kiln (the horseshoe shaped structure) with a pile of broken stone (right) and a small quarry face

Rev. Donald McNicol noted in his report for the Statistical Account of Scotland (1791) that “burning of lime for sale has been begun by adventurers (i.e. entrepreneurs) in Lismore and Appin” but these enterprises were limited by the price of coal, inflated by taxation, and shortage of fuel wood.

The situation changed when, in search of a source of income for the Catholic Seminary that was established at Kilcheran, Bishop John Chisholm built the first lime kiln at Kilcheran in 1804.  Although lime burning continued there for several years, it was not economic and had stopped by the time that the seminarians moved on to the mainland around 1820.

However, with increased demand for lime during the 19th century, kilns were built across Lismore.  In their detailed survey[i], Colin and Paula Martin showed that each set of kilns was built below a cliff so that the quarried stone could be moved downhill to feed the kiln from the top; that they were all by the coast, with a quay for the unloading of coal and export of the lime (carried by the sailing smacks – see the Object for January 2015); and that most had associated buildings (cottages, storehouses for coal, explosives etc).

Limekilns at Sailean (NM836414)

Limekilns at Sailean (NM836414)

The 16 lime kilns of varying sizes, designs and age are at Eilean nan Caorach (NM901468), Alastrath (NM871458), Park (NM884456), Port na Morlachd  (NM867449 and 865448), Sailean (NM836414 and 834412) and Kilcheran (NM825386).  Their history is generally poorly documented, and nothing is known about the Alastrath and Port na Morlach kilns.  All but Kilcheran were probably in operation mid-19thC, when lime burning was a major industry providing welcome employment (estimate of an ouput of 48,000 barrels in 1878).  Park and Eilean nan Caorach continued in operation to WW1 and Sailean to around 1940 but, by then, the industry had been undermined by cheap imports by rail.

Quarrying the limestone was arduous and dangerous work, either hewing by hand or drilling for explosives.  The Lismore object collection includes a set of quarrying tools from Sailean, donated by James MacCormick, late of Killandrist: two heavy duty chisels (43 and 30 cm long) and a long pinch (1.94m long).

LISDD:2009.154 Quarrying chisels from Sailean, as displayed in the museum.

LISDD:2009.154 Quarrying chisels from Sailean, as displayed in the museum.

The limestone was broken into small fragments and fed into the kiln, mixed with coal and lit from the bottom draw hole.  The product, after several days of burning, was quicklime (calcium oxide) in lump form, known as “shell lime” – not to be confused with lime made by burning shells.

Receipt for the shipping of 375 barrels of shell lime from the Park Kilns to Oban for building the new poor house in 1862 (from the collection of copies of Historical Documents, 1851-1900).

Shell lime, which reacts explosively with water to give slaked lime, was an extremely risky cargo, especially when loaded in bulk rather than in barrels.  It was the cause of at least two wrecks of local smacks:  the Janet of Lismore (skipper Hector MacKinnon), sailing north in a severe storm in winter 1870, was forced to seek shelter in Gairloch, but the boat dragged its anchor and went aground.  The crew were saved by a ‘human chain’ of men from the shore but water entered the hull of the smack and it blew up.   Less reactive lime putty or hydrated lime could be prepared on site by slaking the quicklime.  This was a hazardous occupation, requiring considerable skill to produce a product for transport.

Receipt for the shipping of 375 barrels of shell lime from the Park Kilns to Oban for building the new poor house in 1862 (from the collection of copies of Historical Documents, 1851-1900).

Receipt for the shipping of 375 barrels of shell lime from the Park Kilns to Oban for building the new poor house in 1862 (from the collection of copies of Historical Documents, 1851-1900).

 

[i] Martin C, Martin P. (2007).  The Lismore Limekilns.  Unpublished Report for Historic Scotland.

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