I wrote last week about the earlier origins of Kilns and this post focuses on the design and methods employed.
The local design is of a block shaped building of cut stone into which is built a firing chamber, lined with firebricks and insulated with rubble and clay. Recent damage to one of the kilns at Jack Meade’s highlights the technique.
|Damaged Kiln at Jack Meades|
Generally, the kilns (in many sources referred to as draw kilns), had a similarity in design, although variations occur due to local building technique or materials. The firing chamber might also be known as a combustion chamber, crucible, bowl, well or a pot.
The chambers resembled an egg standing on its narrow end with the base and top removed. Generally smooth, this allowed for the lime to slip down and be removed at the base. There are recordings of this design causing the death of some lime burners or others who slipped in and could not claw their way out of the noxious fumes or stifling heat!
|tapered chamber at Jack Meades with leaves blocking the base|
Chambers were loaded with a charge initially – something flammable such as furze or very dry timber which would get the fire going. Onto this the layers of limestone were added with an extra layer of firing material to keep the chamber burning (three to five layers of stone to one layer of firing material). The fuel could be more timber but was probably coal slack or calum. Coal slack is the thick dust that can be found at the end of a coal bucket and was something my grandmother prized for “keeping in the fire” She often collected it for a few days and then wetting it, she would place it over a well lit fire and it kept the fire burning for longer. There is a long tradition in Cheekpoint of importing Welsh coal.
The fire was lit from the base through a draw hole. As the lime was burned down by the heat in the chamber it too was drawn off through these holes. Although many sources refer to these kilns as burning for three to five days as a means of creating lime, its worth speculating that the local kilns may have been able to burn continuously for a longer period, depending on demand
|one large square draw hole, with two smaller beneath|
There could be more than one draw hole, which seems to have been a technique to avoid ash being mixed with the lime. It also allowed more air into the chamber. I imagine these holes could be blocked if required to adjust the burning. The Lime was drawn off into barrels apparently and then loaded onto carts for delivery to farms.
All our local kilns feature a Romanesque arch around the draw hole which provided access to the draw hole and also shelter for those working on them and a place to store tools.
|Romanesque arch typical of local kilns|
Local design seems to have favoured a double kiln. The reason for this would appear to be that once a fire had been lit and the heat had been established in the kiln, it was much easier to get the next burn going and it quickened the process.
|the “charging area” or top of the kiln where limestone
was added to the chamber. Jack Meades.
It’s probably worth mentioning that the double kiln in the field above Jack Meade’s was actually a single kiln originally as can be seen from the distinctive different materials used in both sides. The piece on the left is much younger I would think, which would lead you to speculate on the age of the other. This is in a much greater state of disrepair.
|originally a single kiln, earlier kiln on right|
It has to be said I have never spoken to anyone who remembers the Kilns being used. With the onset of larger machinery and the ability to crush limestone, Kilns became obsolete. As such, the details enclosed are gleamed from books and online sources which I have to admit leads me to speculate on just how accurate my piece is. I found this blog post from Cork which gives more insight, which a reader might enjoy, but to end I found this depiction which I just couldn’t resist. A bit of a yearning here in me I have to say, as there’s nothing like seeing an actual process. It also reminds me, somewhat, of the Kilns at Cheekpoint