Building with cob

Originally posted in 2010. 

A few years ago, at Seed Savers in County Clare, I helped sculpt, pound and pat a house together.

Seed Savers, by the way, is an Irish group that cultivates heirloom varieties of vegetables, which is a lot more important and interesting than it sounds – if any disease or climate problem wipes out the few varieties we use for industrial agriculture, organizations like Seed Savers will be your Noah’s Ark for food. They also give courses in other crafts, though, and this time it was working in cob.

Cob is a mixture of sand, straw and clay – the subsoil under most topsoil will do fine. To make a cob mixture, you combine the elements in a certain ratio and mix them together wet, usually by treading on them with your feet. Then you pick up handfuls of the mixture – the word “cob” comes from an Old English word for “lump” – and stack them on top of each other in a row. Finally, you stand on the row and tread it in, and you get a wall.

The effect is one of sculpting your own building. The straw binds the clay and sand together; instead of a wall’s mass hanging on a few large structures like girders or beams, it hangs on the many tiny structures of the straw. Once the cob dries it can be almost as durable as stone. Bricks are basically cob that has been baked in an oven, and concrete uses a similar principle with gypsum powder, sand and gravel.

Cob’s main disadvantage is that it cannot get damp; for example, a cob wall needs a stone base, as high as the damp rises. In snowy country the stone base would have to be higher to protect against snowdrifts; in this area the problem is moisture. At a conference in Cork a few years ago I spoke with a man who built a cob house in the west of Ireland, and said he needed to put wood cladding on the walls to protect against the area’s driving rain.

Another problem is the lack of understanding from local officials, building inspectors and insurance companies -- it is for this reason, we didn't build in cob ourselves, as well as the fact that we are building in an Irish bog. Because of this, some people use cob to build an "undocumented" house.

One advantage of building with cob is that its thick walls absorb heat in the daytime, releasing it slowly over the night; with southern windows to catch the sun, a cob house can have dramatically reduced heating bills. Still another advantage is that the home can be literally sculpted into a wide range of shapes, with curved walls, bas-relief designs or arched doorways.

Cob can last as long as it is kept dry; the home of Sir Walter Raleigh in England is still standing, as are many other medieval cob homes. It can be built high: seven-story cob towers in the Middle East are still used after hundreds of years.

With a little training, anyone can mix cob together from most local soils. After the walls are given a plaster finish, the house can look just like any other, but made at a fraction of the cost. It's completely ecological, requiring no chemicals or machines, and generating no toxic waste. Insects don’t eat it, it doesn’t decompose and it doesn’t burn. And, of course, it’s dirt cheap.




Top photo: Hayes Barton, birthplace of Walter Raleigh. Bottom photo: cob house, courtesy of Wikicommons.

The past is a foreign country

In the last few months I've been writing a lot about how our modern society differs from any traditional one, and not necessarily for the better. The phrase “traditional societies” covers a lot of ground, of course; basically, I’m defining it as life before we began using energy at the breakneck pace we are today. I mean the cultures that existed before roads became jammed with cars travelling at high speeds, before Hollywood media took over and replaced local culture, and before people in the modernised West began to spend their lives sitting in cars or staring at screens.

Those things didn’t all happen at once, or all together – as I argued a few weeks ago, 1950s America presents a well-studied intermediate case of a somewhat modernised country whose traditional culture was still vibrant and functioning. Ireland in the 1950s, meanwhile, still relied mostly on human and animal labour.

Dividing human societies into the traditional and the modern means making sweeping statements; obviously cavemen lived differently than Ancient Greeks, who lived differently than American pioneers, who lived differently than 20th century Irish. Of course I’m not saying that all traditional peoples lived the same way, or that any of them were wonderful and without tragedy – and of course some were horrific.

I am saying that, despite the superficial differences in language and dress, my elderly neighbours share some commonalities with all the generations who came before them, and -- despite the similarity in accents and dress --  are now culturally separated from their grandchildren in the same village.

Until recently, for example, few humans spent their lives travelling long distances, except for the occasional sailor or nomad. Even most foraging tribes generally travelled over a limited area, and farming people not at all. Like most traditional people, my Irish neighbours grew up tied to a place, knowing it as they knew themselves, and having a responsibility to keep it healthy for their grandchildren. Of course archaeology shows evidence of times and places when humans destroyed the land, often out of ignorance of what they were doing, but more often people lived in the same places for centuries or millennia, which they could not have done if they had not practiced a sustainable kind of management.

Until the last few generations, few people were rootless – even nomadic tribes circulated around a certain area during the year, and were tied to their family. Most modern people tell only the songs and stories manufactured for them by a faraway industry, but traditional people belonged to a landscape and a way of life, to a clan and larger people with their own stories and songs that told of their history. Even if they were poor, most people did not feel poverty as we might today, for their lives were not spend drifting through a sea of strangers.

When my neighbours told me of the history of their place, they described all the local families and their histories, stories of local lords and landowners, rebellions and tragedies – and this despite the land being devastated so often by famine and exodus. Memories don’t reach back so far in the USA, but in small towns here, you meet people who take a similar pride in the place where they belong.

The children in Ireland today have some of these relationships, but you can see it fading as they relate more to Youtube or the latest global teen fad than they do to elders in the same town. In the USA, where this process has been going on the longest, we think of it as normal – we expect that teenagers will relate to the media and not with their families. But most humans in history did not make the same assumptions about young people, and I have heard people from many parts of the world report the same erosion of their local identity.

Until our era people rarely used money, or needed to. Of course money did not exist in prehistoric days, the first 99.9 per cent of human existence, yet those humans traded with other tribes all the same. Even after the ancient Sumerians invented the first coins, though, few people used or even saw a coin even there, and of course most people on Earth were not in Sumeria. A medieval peasant might never have seen money or needed to use it either, they worked, of course, but to grow food and raise animals, like most humans in any time and place. The giant detour that our work makes – to work for someone else, to get pay, to put in a bank, to withdraw, to spend at stores, with governments and companies taking a cut out of every transaction – didn’t exist.

I'm not claiming they lived in an idyllic Eden; of course they could be terrorised by war or disease, but so can many people today --- Westerners have simply been shielded from these realities for a few generations. Keep in mind, also, that medieval peasants might have worked far fewer hours every week than we do. Also, keep in mind that their work was necessary and meaningful, and often done together as a family – it was time spent with the family, not away from it.

Also, I’m not just comparing our modern world with prehistoric or medieval life, with no spectrum in between. My elderly neighbours here, growing up in Ireland in the 1930s, 40s and 50s, would have had money and used it, and even started their own business enterprises at young ages to get pocket money to spend. Those gave them treats, though; most of what they needed they knew how to produce for themselves. Some tell me they didn’t need to use money more than once a week, and that was small amounts from a hiding place.

To give you an idea of how little they needed money, Ireland in the 1970s saw a bank strike that lasted over a year – across the country, no one could withdraw money for more than a year. Of course, some people used a village credit union, or used the post office as a bank, as Irish people do today. Nonetheless, most people’s money was in banks, no one could withdraw for months, and yet life carried on as normal.

You can even see this to some extent in America in the 1950s and 60s – again, a world further along the spectrum to ours, but still less dependent than we are on a constant money stream. Banks then had tellers, not automatic cash machines, and most people visited them once or twice a week. People went shopping less, and instead of the dizzying number of products our stores carry, shops had staples that people used for cooking, or simple clothes that were more durable. ATMs didn’t exist, but people didn’t need them.

In every society that I know of – except our modern one -- children learned from parents and older relatives, and stayed close to their families until they came of age. In most of those children accompanied their parents as they hunted, ploughed, washed clothes, cooked food and all the other necessities of life, and learned the skills they needed to be adults. Children in more recent centuries went to schools, as my elderly neighbours did, but most countries children could walk to school, were taught by local people who were also part of the community. Most did not do what parents often do today, to send their children away to giant cement compounds to be raised by strangers.

In early America, for that matter, school took fewer hours of the day and fewer days of the year. They did not experience what modern children do, of being warehoused for 20,000 hours of their formative years. Yet many of those schools taught students far more, at earlier ages, than under our giant bureaucracies. If you want to see the level of education that many rural children received, read the letters of Civil War soldiers conscripted from homesteads. Or keep in mind that the Lincoln-Douglas debates, whose complex sentences often flummox college students today, were meant to be listened to, not read, and by simple farmers.

Until our modern society came along, no people shut their elders away in nursing homes, rarely seen by children and grandchildren and with only other dying people for company. In most traditional cultures elderly members of a family lived with their children or relatives, and most religions had some variation of the fourth commandment to honour one’s father and mother. Elders, though weakened in body, had a lifetime of experience that younger generations needed, whether in raising children, dealing with neighbours or handling emergencies. From a position of respect they could pass on the songs and stories of their people, giving children an umbilical link to the generations who came before.

We see the same pattern in other animals with some intelligence and family life; elephants, for example, need the elder members of the herd to keep the younger ones in line and show them how to deal with threats. When park rangers in South Africa introduced young elephants to a new preserve, after the older members of the herd had been killed, they found the young animals made unwise decisions for decades, only slowly learning, through trial and error, the right way to live. For generations many people in America today have grown up in the same situation, without elders to guide them through their lives, until we now have a population of children in adult bodies.

Just as most traditional peoples did not spend their work hours staring at a glowing rectangle, so they did not spend their leisure the same way. Children had games that were passed down for centuries – blind-man’s bluff and Johnny jump-up – that are only now disappearing in an age of video-games. Elders sang songs that told people who they were as a people, told stories of love and loss, of heroes and maidens, tragedy and humour and the human condition. My neighbours grew up with families visiting each other at night, gathering with the local storytellers and musicians, listening to the tales and singing along to folk songs they all knew, which had been passed down through the generations.

The modern era has changed our friendships as well; almost any humans in history, whether prehistoric tribes or medieval farmers, Hebrew herdsmen or American pioneers, dealt with a community of people outside their family who lived nearby, and had to maintain good relations with them. Small-town people, whether here or in the USA, retain some of this attitude even today; they have to know their neighbours and help out occasionally, as they might need help themselves.

You see the difference in the way my neighbours treat death with the way modern urban people do. When I lived in the modern city and a neighbour died, we found out when an ambulance parked outside, or a new couple moved in where the old lady used to live. Out here in rural Ireland, a neighbour’s death meant girls at the local school without a father, an empty chair at the pub, a voice missing from the hymns at church, a hole in people’s lives.

Such relationships soften our reactions to conflict; the person waiting in line ahead of us might have taken First Communion with us, and might have scored the winning goal in the school’s football match long ago, and might have a tractor we need in case a tree falls over the only road. Again, the details would change from one culture to the next, but every human society would have a web of debt and obligation like this, to temper our reactions to conflict and force us to see other people’s views. Enough threads like that, woven together, form a civilised society.

Only in the modern era, for most Westerners today, do “friends” largely mean icons on a screen, whose relationship with you consists of moving electrons around. Today we can “meet,” have “conversations,” “share” news, and even “date,” all without ever having to deal with the inhibiting presence of other humans. We can do these things under fake names and pictures, talking to people we will never meet in person, and say or do whatever we want without fear of consequences. People can appear and disappear from our lives, all without leaving any tangible presence, fading like ghosts when bored. 

The modern world has many advantages; until the last century food could be scarce, and even in good years it cost labour and sacrifice. At the same time, until the last century no humans ate food that had been flown across the world, packaged in chemical gases to preserve it and simulate a healthy colour. No humans ate food injected with other chemicals to make it more addictive. Instead, traditional people ate foods they knew, and had picked out of the ground or off a tree. Foods belonged to certain seasons, and tasted like a time and place. Meat came from an animal, hunted or herded, that had just been killed, unless it was salted and smoked. People recognised their food as precious and its sharing as sacred, the stuff of religious ritual.

Until ours came along, all human societies had rites of passage to mark when a girl became a woman, and when a boy had proven himself a man. Becoming a young man or maiden – what we today call a “teen” -- did not mean that they would spend more hours warehoused in an institution, or spend their time with gangs of other teenagers in places of maximum temptation; rather, it meant taking on more of the responsibilities of adulthood, preferably with older family and mentors to guide them.

Again, a childhood among the Bushmen or the Vikings would be very different from each other, and both would be very different than American pioneer children or mid-20th-century Irish. Each of these eras had injustice, disease and starvation, just as ours does. My point is that we are not sealed in a culture of driving and staring at screens, with all its advantages and disadvantages in a single package.

The past, with all its possibilities, is still there. We know what more traditional people did well that we do not. We can still grow, cook and preserve food without electricity, play the games and tell the stories that our forebears did, and sing the songs that told of their loves and tragedies. We can learn from the elders who remember these things, before the last of them disappear and the past becomes an utterly foreign country to us.

Burning the Bones of the Earth

Originally published at Low-Tech Magazine, September 2013. 

Explore the now-ruined estates of the Irish countryside and you occasionally find a stone cylinder, as much as several metres high and wide, open at the top and with a small door at the base. Some resemble the medieval fortresses that still dot the landscape here -- but no one built fortresses so tiny, or half-buried in the side of a hill.

In fact, they are kilns for lime burning, a now-forgotten industry that sustained many agrarian communities before energy became cheap.

“Lime” here means neither the citrus fruit nor the tree, but refers to a white powder derived from limestone. For at least 7,000 years humans created lime in kilns, as they might have hardened pottery or smelted ore, and used the material for dozens of purposes now largely replaced by fossil-fuel by-products – perhaps most commonly to create mortar for construction.

British and Irish farmers, though, found it most important to neutralise acid soils and multiply crop production – as much as fourfold, by some contemporary accounts. For hundreds of years until the mid-20th century, lime supported a vast and vital network of village industry -- quarries to mine the limestone, carts and barges to transport it, and specialists to monitor the burning. In the late 1700s, according to one survey, County Cork alone was said to contain an amazing 23,000 kilns, or one every 80 acres. (1)

Limestone is mainly coral and shells of long-extinct sea creatures, squeezed over aeons into a solid mass of calcium carbonate, or CaCO3.  When burned at 900 degrees C or more it vents carbon dioxide (CO2), leaving behind the volatile calcium oxide (CaO) – “quicklime,” “burnt lime” or “unslaked lime.” Then, when combined with water – hydrated or “slaked” -- the quicklime became calcium hydroxide or Ca(OH)2, and could be put to many uses. Confusingly, all of these have been called “lime” at times, but in this article, we will call the original rock “limestone,” the caustic material from the kiln “quicklime,” and the hydrated final product “lime” for clarity.  

Roman Concrete

The earliest use of lime dates to present-day Turkey between 7,000 and 14,000 years ago, and many ancient civilisations used it to create mortar between stones. The Romans, however, took lime a step further, mixing it with various other ingredients to create an early version of cement. In fact, their version has proven superior to our own in some ways. Our concrete lasts only decades – as little as a single decade in seawater -- while Romans created concrete that not only formed in seawater, but have withstood the pounding of waves for 2,000 years.

The secret, according to two papers released in the summer of 2013, involved mixing quicklime with volcanic ash to form mortar. Volcanic ash was plentifully gathered from the volcano at Vesuvius, according to Pliny the Elder – ironically, the same volcano that would later kill him. Romans then packed this mortar into wooden forms and lowered them into seawater, which caused the quicklime to react and form a lime-and-ash mix of waterproof cement.

The papers’ authors say such techniques could prove useful even today; not only did their concretes stand up to time and the elements better than ours, but such methods are “greener” – generating less carbon emission – than our cement manufacture. Crushing rocks into Portland cement powder requires enormous quantities of energy and accounts for seven per cent of all industrial carbon emissions on the planet. (2) (3) (4) (5) (6)

Romans brought such technologies with them as they spread across Europe, so lime kilns appeared in Britain with their invasion and disappeared for several hundred years after they left. In Ireland, where Romans never set foot, Normans apparently brought the technology in the 1200s, to build the round towers that still frequently stand today. (7)

Whitewash, Limelight and other applications

Lime also forms the basis of whitewash, used for centuries to protect and brighten structures, fences, vehicles and even trees, without the alarming and unpronounceable stew of toxic ingredients in many modern paints. Whitewash is fundamentally a mix of lime and water, although it could also contain salt, milk, linseed oil for water-proofing, or hair or cereal husks for strength.

The dried lime was safe to handle and even for animals to lick, but remained mildly alkaline enough to disinfect barn and dairy walls. Its brilliant whiteness was valued in places like Britain and Ireland, where the winters grow very dark – Irish cottages were traditionally whitewashed in spring and again before Christmas. In sunnier climates, however, that same colour helped keep buildings cool.

Lime had many other uses: Farmers rubbed it on their livestock’s feet as an antiseptic, or painted it onto fruit trees to prevent fungal diseases. Some mixed a bit of lime into well-water to disinfect it, or to preserve eggs for months without spoiling. Tanners used it to remove hair from hides, gardeners to repel slugs and snails, printers to bleach paper.

Even the corrosive quicklime, the calcium oxide that came straight from the kiln, had many uses before it was hydrated. It kept pantries and store-rooms dry – the 1915 household manual “The Best Way” recommended keeping a bowl of it to reduce humidity, as it sucked moisture from the air. It caught fire easily – sometimes too easily – and was used to make an early, high-intensity lamp for the stage – the original limelight. (8)

Lime kiln in Porthgain, Wales. Picture: Aelwyn.

It also made a rather fearsome weapon, as it could sear the skin and blind the eyes. In David Hume’s A History of England, he recounts a battle between English and French ships around 1216, in which the English captain Phillip d’Albiney ingeniously used quicklime to turn the tide of battle. He saw that the winds were blowing from his ships to French fleet, and “having gained the wind of the French, he came down upon them with violence; and throwing in their faces a great quantity of quick lime, which he purposely carried on board, he so blinded them, that they were disabled from defending themselves.”

The compound made a handy terrorist weapon as well; when Irish reformer Charles Parnell spoke at a political rally in 1891, someone in the crowd threw quicklime at his face, and “had not [he] shut his eyes in time, he would undoubtedly have been blinded,” his wife Katherine later wrote.

Quicklime was also shovelled into graves to decompose bodies more quickly, as Oscar Wilde saw when he was a prisoner at Reading Gaol (Jail) in Britain:

And all the while the burning lime
Eats flesh and bone away
It eats the brittle bone by night
And the soft flesh by the day
It eats the flesh and bone by turns
But eats the heart away.

Lime in Agriculture: Sweetening the Soil

Its use in agriculture, however, eclipsed any other use on these islands, so valuable was its ability to turn acid bog-lands into croplands. Some 40 per cent of the arable land in the world is too acidic for many plants to grow – the more acidic the soil, the more toxic aluminium plants absorb. These days, farmers often treat such soils with crushed limestone or other energy-intensive products, and scientists like Chris Gustafson of the University of Missouri are trying to genetically engineer aluminium-resistant crops. In earlier eras, however, farmers found that lime temporarily “sweetened” or neutralised the soil. (9)

This made lime so valuable that many agrarian communities supported a network of local industries to create it -- quarries to mine the limestone, wagons to transport the rocks by road or barges by canal, and specialists to supervise the burning. By the mid-1600s many families in County Cork, Ireland, for example, paid their rent by lime-burning on the side, according to a civil survey of the time. (10)

Farmers treated the soil in quite a straightforward manner: they shovelled quicklime straight from the kiln onto a horse-drawn cart, drove the cart to the needed field and drove the horse back and forth across it as though ploughing. Every several metres the farmer stopped the cart and scooped several shovels of quicklime in “falls” on the ground -- six to eight barrels to the acre.

Spreading a highly caustic compound onto cropland might sound inadvisable, but the next rain both hydrated it into lime and soaked it into the ground. Transporting the quicklime, however, was dangerous work, as it could spontaneously burst into flame and burn carts and barns, or simply to eat through wooden containers if it wasn’t spread quickly. (11) (12)

The process only sweetened the land for a limited amount of time, according to contemporary reports – three years in some fields, twelve years in others, depending on conditions. In any case liming had to be continually re-applied or it “enriched the father but impoverished the son,” went the saying, so the kilns were kept in steady business.  (13)

Operating the Kiln

Kilns themselves needed to be carefully situated: they needed to be as close as possible to quarries, so that hundreds of tonnes of rock could be carried with as little effort as possible, by horse or barge. At the same time they had to lie as close to the lime’s destination as possible – a fortress or church being built with mortar, or fields that needed sweetening -- so that the quicklime could also be transported without incident. Moreover, they could not be situated near populated areas or even campsites, as the burning lime gave off noxious and potentially lethal gases.

The brick or stone structures were often built into hillsides to allow people to easily transport coal and lime to the open top, or mouth, and were often several metres across and about as high. On the inside they usually tapered down so that gravity alone fed the fuel down, and at the narrow bottom of the cone, one wall had an arched opening or “eye.”

The kiln had to be filled carefully, with precisely measured amounts and materials – if the lime did not bake at a high enough temperature for long enough, the stone would not transform into quicklime and the work would be in vain. Lime-burners filled the bottom of the kiln with the driest wood possible – furze-wood was often mentioned – and then the men lay alternating layers of fuel and limestone.

Perhaps the most common fuel was “colm” – anthracite coal – although charcoal could also be used, as well as “turf” – dried peat from the bogs here. Whatever the fuel, it had to be in an opaque layer, insulating the chunks of limestone from the sides of the kiln and from each other, according to old lime-burners interviewed decades later for Irish national radio.

Sleeping by the Kiln

Once the kiln was filled, the wood – at the bottom of the kiln, by that little door – was set on fire, and that, in turn, lit the fuel through the rest of the structure. Once the kiln was lit there was no going back; the lime-burners had to maintain a watch over the kiln for the next three or four days, sleeping nearby. Burning was often done in winter, when there were fewer farm chores to be done, so it must have been tempting for men sleeping out in the cold to move closer to the warm glow of the kiln. 

According to lime expert Colin Richards, however, sleeping by the kiln was extremely dangerous, between the poison gases and the open pit. There were cases of itinerants sleeping near the mouth for warmth, he said, rolling into it as they slept and being roasted alive.

Certainly the men did exhausting work for days at a stretch, making them “thirsty as a lime-burner” as the saying went. A single kiln could hold a hundred tonnes of material, which had to be shovelled in by hand, yet delicately measured and arranged inside.  Of course there was less to shovel out – the coal had burned away, and the limestone had lost some of its mass – but that material was much more difficult to handle.

“Drawing out the lime underneath was the dirtiest part of it,” said one anonymous lime-burner who worked in Ireland in the 1930s and 40s and was interviewed for a radio documentary in 1981. “It was there that you got the dust, and you got too much of it and you began bleeding from the nostrils.”

Magic and Ritual

With their furnace-like heat, poison vapours, alchemical transformations, hazardous products and vital importance to agrarian survival, it was perhaps inevitable that farmers associated kilns with all kinds of magic and ritual. According to Irish elders interviewed in the 1930s, young people often performed Halloween rituals around lime-kilns to find out who they would marry.

In one instance, fairies were said to have killed off a farmer’s livestock after he inadvertently built a kiln in their way. Other peoples were said to have summoned evil spirits there; a reverend in Carnmoney, rumoured to have sold his soul to the Devil, was said to have courteously invited him to a kiln so the Devil would feel at home. (15)(16)(17) The lime burners themselves had a simpler ritual, one they said was practiced among “all the lime burners of old.”

“You took a bottle with you that morning … of holy water,” one said, and before the kiln was fired up “you just sprinkled it on top the stones, and made the Sign of the Cross, for you were burning – what they used to say was -- you were burning the bones of the Earth.”

Notes:

(1) Topographical Directory of County Down, by Samuel Lewis, 1837.

(2) “Microscopy of historic mortars — a review,” by J. Elsen, Cement and Concrete Research, July 2005

(3)  “Chemistry and Technology of Lime and Limestone,” J. Elsen, Cement and Concrete Research, December 2005

(4)  “Material and elastic properties of Al-tobermorite in ancient Roman seawater concrete,” by Marie D. Jackson, Juhyuk Moon, Emanuele Gotti, Rae Taylor, Abdul-Hamid Emwas, Cagla Meral, Peter Guttmann, Pierre Levitz, Hans-Rudolf Wenk, and Paulo J. M. Monteiro, Journal of the American Ceramic Society.

(5) “Unlocking the secrets of Al-tobermorite in Roman seawater concrete,” by Marie D. Jackson, Sejung Rosie Chae, Sean R. Mulcahy, Cagla Meral, Rae Taylor, Penghui Li, Abdul-Hamid Emwas, Juhyuk Moon, Seyoon Yoon, Gabriele Vola, Hans-Rudolf Wenk, and Paulo J. M. Monteiro, American Mineralogist.

(6) “Roman Seawater Concrete Holds the Secret to Cutting Carbon Emissions,” Berkeley, http://newscenter.lbl.gov/news-releases/2013/06/04/roman-concrete/

(7) “Pre-industrial  Lime Kilns,” English Heritage, May 2011

(8) The Best Way - A Book Of Household Hints & Recipes, 1915

(9) “Famine Fighter,” Illumination magazine, Spring / Summer 2013

(10)  The Ancient and Present State of the County and City of Cork, by C. Smith, 1815 edition.

(11)  “Burning the Bones of the Earth,” a documentary by Radio Telefis Eireann, 1981

(12)  Edwardian Farm, BBC Television

(13)  Essay on the Use of Lime as a Manure, by M. Puvis, 1836.

(14) “Pre-industrial  Lime Kilns,” English Heritage, May 2011.

(15)  Maureen Cunney, Currower, Attymass, Ballina, County Mayo, as part of the 1937-38 schools initiative.

(16) Researches in the South of Ireland, by Thomas Crofton Croker, p. 82

(17) Irish Witchcraft and Demonology, by St. John D. Seymour, [1913]

Lime kiln in Prague. Picture by Radim Stezka.