One of the most intriguing aspects of Irish salt manufacture is its association with lime; whereby both commodities were produced using the same source of combustion. Historical references to the practice suggest this was a uniquely Irish solution to fuel poverty. By using the heat generated by large lime kilns the process promised to be more productive and was first documented in 1757 (Ludlow 1994, 67-8). In Cork, the proprietors of salt and lime kilns convinced local butter makers that salt produced on pans fuelled by coal fires was inferior to that from lime kilns (Rynne 1999, 29).
Combination burning was not restricted to lime/salt in Ireland – we have evidence that kelp burning (reducing seaweed to soda for the textile industry) was combined with salt too. For example in the Rosses islands of west Donegal a large facility was designed specifically for this purpose, however most manufacturers were content to set the evaporation pans on top of existing kelp kilns.
With this in mind we have been conscious of the appearance of lime kilns within the vicinity of known salt-working sites. Although not in a position to visit all of these monuments, we nevertheless have been keen to see evidence of the modification of these sites to accommodate iron evaporation pans. Few lime kilns are in pristine condition, some have been modified or restored, and when accessible to the public the upper aperture to the kiln pot is inevitably capped. At the village of Killough in Co. Down the salt manufactory is a substantial two-storey building and yard. The stone building features doors and windows with brick or stone arches and some window frames are still in place. It is now roofless and the interior walls and divisions have been removed.
Salt was produced in Killough from c.1723 and three pans are noted as in use in 1727-8. The first entry of rock salt being imported through Strangford, the customs office for Killough, occurred in the year ending March 25, 1724. Killough used rock salt imported from Liverpool and coal from Ayrshire or Whitehaven as fuel. From the limited information available it would appear that much of the output from Killough was shipped in bulk to merchants in Belfast, Newry, Dundalk, Drogheda and Dublin. The last reference to Killough functioning as a salt works is 1845 – this date is rather late given the decline of other salt works in Ulster and it may be that production struggled on by using the nearby lime kiln.
Outside the salt works on the waterfront is a substantial lime kiln featuring a draw hole on the pier and an earth / stone ramp providing access to the kiln pot above. Unusually the top of the kiln is castellated.
The aperture to the pot on top of the kiln is capped, but around it are a four iron fittings that may have secured the evaporation pans for salt production.
Killough provides tantalizing evidence of what was once a wide-spread practice in Ireland. Similar sites on our list for future survey include Mallow in Co. Cork, where Colin Rynne has noted further evidence of combination burning – updates to follow!