Thursday 23 January 2014
Wednesday 22 January 2014
Yesterday I listened, over and over, to interviews with Domincan brothers and other scholars in 1974, discussing the 700th anniversary of the death of Thomas Aquinas, and found myself fascinated by the depth of their knowledge and passion. The men whose voices I heard, as though sitting beside me, went to their graves long ago, as did most of the nuns I knew as a child. The world they represented -- almost two thousand years of scholarship and scholasticism, cloisters and sanctuaries, have almost disappeared now, and few people remember they existed, or why they had value.
As baffling as this sounds to most people, we need a world of monasteries again. We need a world of people who approach the Divine with modesty rather than flamboyance, who can live self-sufficiently even when the dominant culture collapses, who can practice self-control in all things, who believe in preserving the best of human knowledge for later generations.
"Aquinas begins by discussing how we can talk about God, and demonstrates that in a sense we can’t, because we’re trapped in our language and experience. The very structure of our language presupposes that we are dealing with our human experience and limits; our grammar and vocabulary walls our world.
Aquinas said that we should take the words as far as we can, and only when the words break are we led to the mystery. He famously said on his deathbed that all his words were like straw. But he understood that, and wanted to make the best straw a human could.
Few people remember what scholasticism was, but Aquinas saw it was vital in retaining human dignity. To Aquinas, the fact that we can logically demonstrate that we have something hidden in our being, something beyond all reason but essentially human, whether we are talking about a baby or an aged person, is what allows us to act as moral beings. It keeps us from being monsters. It is what allowed us to be capex infiniti – beings of unlimited horizons."
-- paraphrased from Dominican friar Herbert McCabe of Oxford University, interviewed 1974.
Saturday 18 January 2014
Article originally appeared in Low-Tech Magazine.
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 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.
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)
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)
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.
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)
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.
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.”
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.”
(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, 
Sunday 12 January 2014
|Cob house I helped build in County Clare.
This assumption of convenience has shaped how we build houses, how we eat, and how we dress for all seasons. It also means that a fuel crisis or depression – or the winter storm that cut power to half a million North Americans a few weeks ago – can leave us completely vulnerable.
Consider, then, that people lived for thousands of years in wintry lands without a thermostat to crank, or without any modern fuel or technology, and obviously did not all freeze to death – nor were they even necessarily uncomfortable. They built their homes differently than we do, they adopted different dress and habits, and lived with a different set of expectations.
Traditional homes in many cultures had thick walls, whose thermal mass absorbed heat during the day and radiated it back during the cool night. Some homes in Ireland, for example, were made of cob – a mixture of sand, clay and straw that could be literally sculpted into a house. I helped built one in County Clare, Ireland, and I’m told it remains cozy inside years later.
In many cultures – whether medieval Wales, pre-Columbian America or Ancient Greece – villages were arranged to maximize exposure to sun and light, minimizing the need for burning fuel. Only in recent times have we decided to build without regard to direction or landscape. (1)
“Coupled with other low-tech solutions … passive solar design could all but eliminate the use of fossil fuels and biomass for heating buildings throughout large parts of the world,” wrote Kris De Decker in Low-Tech Magazine. (2)
Of course, many homes used to be easier to heat and insulate, for the simple reason that they were smaller. As recently as 1950, the average new home in the United States was 983 square feet, not much larger than old Irish cottages. By 2004, however, the average had swelled to 2,349 square feet, even though family size had shrunk, and most homes were occupied by just one or a few people. (3)
Realistically, of course, most of us are not going to design new cities or even houses – even if you have an opportunity to build your own home, as we did, budgets and local ordinances might force a compromise with convention. Most people rent or pay a mortgage on an already-built home, and have to retrofit.
Thankfully, retrofitting can go a long way, starting with insulation; according to one organization, 65 percent of American homes have substandard insulation. That wasted energy – whether at the electrical power plant or in the home – has a real human cost; according to a 2003 study, retrofits across the United States would mean 6,500 fewer asthma attacks, and save hundreds of lives and $1.3 billion in health costs. That doesn’t even count the billions we would save in heating costs, the fossil fuels saved for future generations, and the greenhouse gases left un-gassed. (4) (5)
For people who can’t afford new insulation, old clothes stuffed in the attic could also help. Victorians used to insulate inside by putting old wine bottles – empty but re-corked – under the floorboards, creating air pockets. People can simply close off outer rooms and seal them off, keeping heat in areas where people spend most of their time. Trees and vine trellises, moreover, can be positioned to shade homes in the heat and let light through in the bare-branched winter.
You could create your own thermal mass inside your home. A trombe wall is a thermal mass – bricks, black-painted water tanks, anything to absorb heat during the day and radiate it at night. It would usually face the south (if you’re in the Northern Hemisphere), and sit inside your windows – but if you want to build a greenhouse, you could build it on the south side and make your outside wall the thermal mass. (6)
What all these approaches have in common is that they maximize external energy coming into your home (south-facing windows, trombe wall) and keep the heat that’s there from escaping (insulation). All of them, though, involve building or installing something new, and some solutions are even more basic than that – so much so that they are often overlooked. More on that next column.
Originally published at Grit magazine.
Thanks for the patience; our internet has been off and on lately.
(1) A Golden Thread: 2,500 Years of Solar Architecture and Technology by Ken Butti and Jon Perlin, as cited in “The solar envelope: how to heat and cool cities without fossil fuels,” by Kris De Decker, Low-Tech Magazine.
(2) “The solar envelope: how to heat and cool cities without fossil fuels,” by Kris De Decker, Low-Tech Magazine.
(3) “Americans want smaller homes, not McMansions,” USA Today, August 25, 2010.
(5) “The Public Health Benefits of Insulation Retrofits in Existing Housing in the United States,” Jonathan I. Levy, Yurika Nishioka and John D. Spengler, Environmental Health: A Global Access Science Source, April, 2003
(6) The Passive Solar Energy Book by Ed Mazria.