| Muck and Mystery Loitering With Intent |
blog - at - crumbtrail.org |
One of my secret, sometimes guilty pleasures is reading a variety of things on the net and allowing them to mingle in my mind, sometimes sparking connections that may or may not be valid when investigated further.
For example, a message from a biochar/gasification list today noted that the type of charcoal making system used for centuries in the western part of Maharashtra State, India used what we now call TLUD (Top Lit UpDraft) technology. TLUD stove designs on a small scale are advocated as a simple, cheap but effective improvement on the old 3 stones and a pot cooking system, and which also produces biochar if the burn is quenched at the right moment.
The TLUD idea is that air flow through the feedstock is controlled so that it is mostly the pyrolysis gases given off from heating the feedstock that burn rather than the feedstock itself. The traditional charcoal making system in India did the same thing. In the words of the message author, A.D. Karve:
The wood to be charred is heaped on the ground and the heap is covered with mud to form a crude kiln. An opening is left in the mud plaster at the top and there are also a few openings at the base of the kiln. The wood is ignited through the opening at the top of the kiln. The openings at the base provide the air. The fire traverses from top to bottom, leaving charcoal behind, while the air traverses from the bottom to the top, providing oxygen to the zone where wood is burning. The air passing through the charcoal zone is devoid of oxygen. This air, which also contains tar vapour, passes out of the kiln through the top opening. The kiln keeps burning for several days. When the fire reaches the bottom of the kiln, the smoke coming out of the top opening is no longer black, because it no longer contains tar. After this stage, it is the charcoal that burns. The changed colour of the flue gas is an indication that the charring is complete. Then the holes at the bottom and also the one at the top are sealed with mud to quench the fire. The charcoal is removed after the mass has cooled.How did this system get invented?
'Who do you think made the first stone spear?" asks Temple Grandin. "That wasn't the yakkity yaks sitting around the campfire. It was some Asperger sitting in the back of a cave figuring out how to chip rocks into spearheads. Without some autistic traits you wouldn't even have a recording device to record this conversation on." . . .The possibly spurious connection that I got was that like the caveman obsessively chipping stones it was some ancient Indian geek with sub-par social skills who made the TLUD charcoal kiln. But that's not the end of this chain of connections. When you read up on the eons old system of metallurgy in India, especially steel making, that TLUD kiln may have been an important part. The same design used for making charcoal is also capable of producing the high heat needed for making quality steel. Instead of quenching the reaction once it reaches the bottom, increase the air flow and you have a charcoal burning blast furnace.She has always thought socializing was boring, and she famously described herself as "an anthropologist on Mars" to neurologist Oliver Sacks when explaining her interactions with typical people. As a teenager, while her peers fixated on boys and pop culture, Ms. Grandin was consumed with scientific experiments. . .
People on the "spectrum" tend to be just as obsessed with things and the way things work as they are uninterested in social relationships. And, as Ms. Grandin observed, people interested in things make important advancements—particularly in engineering, science and technology. . .
"It's important to get these autistic kids out and exposed to stuff. You've got to fill up the database." Silicon Valley and the tech companies are like "heaven on earth for the geeks and the nerds. And I want to see more and more of these smart kids going into the tech industry and inventing things—that's what makes America great."
When you read the sparse accounts of ancient steel making in India, especially what is called Damascus steel made from wootz eggs imported from India, the methods seem very much like the traditional charcoal kilns still used today in some parts of India, though they have forgotten how to make the wootz. The fuzzy story is that small amounts of iron ore mixed with some charcoal and other impurities, and encased in clay containers, were inserted into such kilns and left to endure the inferno through the whole process from start to finish. The resulting high carbon steel alloyed perhaps with vanadium impurities was world renowned - once properly refired and hammered into blades (folding, pickling, yada yada) - for its quality and beauty.
In the Amazon where Terra Preta was discovered they lacked ores and didn't do metallurgy. But, they did pottery - big pottery if the archaeologists can be believed. They obviously had to have had kiln technology. They had wood and mud, so it seems that the type of TLUD system used in India could have been done there too, but we would have no record of it now since such kilns would not have survived the ages since then. Also, wherever Terra Preta is found it is littered with broken pottery. Perhaps such sites weren't just middens, the garbage dumps and land fills of antiquity. Perhaps they were potter sites which would in the normal course of events become suffused with charcoal and failed, broken pots.
The Amazonians would have had their fair share of geeks too. In addition to my imagined potter geeks obsessively playing with fire and mud the way that the notional cave man sat chipping his stones, there might have been agro-geeks who noticed that abandoned potter sites grew magnificient weeds and so would make really good kitchen gardens. In this way the Terra Preta super soil system wouldn't have to have been invented from scratch, derived from first principles. It was generations of diverse geeks each hyper focused on a singular obsession.
This doesn't neatly tie up all the factors of this mystery since there are also areas of extensive semi-improved ag lands in the Amazon - the Terra Mulata areas that are better but not as good as the Terra Preta spots - but they might be understood as later and lesser applications of the same principles but achieved with a variant of the standard slash and burn swidden system - slash and char. Some geek had an inspiration, or maybe just enjoyed fire experiments.
Pottery was my first professional experience as a working artist. I was a production potter for well over a decade after art school. Beyond form and function, it catered precisely to the science geek in me. Potters formulate their own glazes and clays, sometimes with very complex chemical forumulae and carefully documented experimentation. Potters are a real life example of why a scientist must have superb skills of documentation. Different substances and combinations of substances behave differently at different temperatures and atmospheres within the kiln. Many of us also studied kiln design and built our own, becoming fairly well-versed in the technology and the use of various sources of heat such as wood, gas, oil, electricity, etc. It's no surprise that historical potters and ceramists were a huge part of geekdom and the development of a number of technologies down through the ages.
"Some geek had an inspiration, or maybe just enjoyed fire experiments."
It was always regarded as an inherent truth among potters that we were all bonafide pyros who'd found a safer, more productive way to practice our obsession.
Posted by: Jeffrey at February 24, 2010 09:35 AMHaving been diagnosed Bi-polar(3years ago) and scoring fairly high on those online aspergers tests,
I like to think that many innovations/advances have come from people who are a bit "off"/"eccentric", or
"on the spectrum". I too enjoy reading a variety of things on the net and making connections between them, however it more often happens by following links, opening new tabs and googling a term, or something prompting me to recall something read/heard years ago then searching it,etc.
Awhile back we had a burn(weeds/construction debris) and some aluminum(cans?) melted into nice little nuggets, this made me think of casting ingots and led me to google "diy foundry". That led to a bunch of things, one of which was making your own hardwood charcoal where they described
the TLUD method in a 55gl drum. I also read up a little on the history of smelting iron and learned
that bloomeries preceded blast furnaces; that nickel/iron meteorites may have been the first sources of ore(egypt?); that eskimos (canada?) cold hammered tools from a huge meteorite. Somewhere in that process I thought about damascus
steel, which I had read about in a Louis L'amour book(walking drum?)[the book also mentioned the origin of the assasins & manufacture of black powder] this of course led to another search.
I read about wootz steel being the basis for the damascus blades; that modern smiths haven't been able to duplicate the blades, except by forging wire rope; the wootz steel may have come from a specific ore body that was depleated. After that I searched "black powder" & followed a link to "cordite" where I learned that T.V./Hollywood gets
it wrong when they say "you can smell the cordite"
as it was only used for a brief time(late 18-early 1900's?) and modern smokeless powders use different propellants. Black powder must have come from some geeky chinese guy, you'd have to be kinda anti-social to collect dehydrated urine(saltpeter) & grind it up with charcoal & sulpher; why would you even think to try it in the first place? I think the internet could be a force multiplyer for the geeks of the world. Back 40, didn't you do a post a while back, something like
"is the net making us stupid?"?
-jw
I don't think that the net makes us stupid, quite the opposite. But I may have quoted someone who does in order to argue against them or something like that. Nothing comes to mind. If you have something specific to cite then perhaps I can reconcile the issue.
I'm more of an open source, information and communications technology, home brew, people's science sort of fellow and the net is an important part of that.
There are dangers with information. People can get dumbed down by talking to one another. That's always and everywhere been true but it's faster and easier with ICT, as is everything else. There are good points and bad points.
Posted by: back40 at February 24, 2010 06:55 PMA bloomery is a type of blast furnace, but it may be a more precise characterization of the sort of smelter that I imagined evolving from a mud walled TLUD in India. Also the wootz may be more precisely described as "sponge" iron, the typical output of a bloomery.
You could go back through the post substituting words and adding a bit more description and end up with something closer to your take on the subject though not actually different from mine.
It is an interesting subject to me. It got drive by treatment above since I was on my way to the Amazon to make pots and play in the dirt.
Posted by: back40 at February 24, 2010 07:21 PMWhile I'm nattering geekily about arcana, there's something else about pottery that I've fuzzily connected to Terra Preta.
Jeffrey says: "Potters formulate their own glazes and clays, sometimes with very complex chemical forumulae and carefully documented experimentation."
Manganese is one of the minerals used in glazes and is also a very important mineral in soil chemistry. Could it be that Terra Preta is rich in manganese due to the pottery shards it contains, and so has a high redox potential? The manganese wouldn't all be available at once but over the centuries it would gradually weather out of the pots.
Posted by: back40 at February 24, 2010 08:00 PMI can't speak to Terra Preta having manganese in the soil due to the pottery, but manganese is indeed an oxide used as a colorant in glazes, just like other metal oxides such as copper carbonate and iron oxide. It's also a bit of a flux. Some naturally occurring clays contain manganese as well. Just as we here in Missouri have clays rich in iron oxides, clays from other regions might contain manganese, so it's certainly a possibility depending on how much manganese - if any - was actually used in the clay, slips, or glazes in question.
Posted by: Jeffrey at February 24, 2010 09:16 PM@response 1. I WASN"T trying to say that you think the net is making us dumb, quite the contrary, my point was that by reading various things on the net and then making connections the net could be a force multiplyer(lush pasture). O.K. the post was "seasonal bloviation" jan 8, 2010 in response to the question "how is the internet changing the way we think?"(not "is the net making us stupid?") you wrote "The internet doesn't really change any of that. By analogy it's a lush, irrigated pasture rather than a semi-arid and sparsely vegetated open range. But the herbivore that grazes it still has to chew and digest just as much, it's just faster and easier to get a belly full."
@response 2. I wasn't trying to dispute anything in your post,or have a different take on the subject. I was just sharing the process that I go through making connections, seeing as it covers some of the same ground.
As for the pot shards/manganese, that sounds plausible. Most of the shards I've found in the S.W. are pretty porous, maybe, like bio-char they
could provide habitat for beneficial micro organisms & increase water holding ability? I roll
my own smokes and in the AZ summer a can of tobacco can get pretty darn dry, so I take a 1in.
piece of saltillo tile soaked in water, pat it dry
& toss it in the can- instant humidor
-jw