Tag: Metallurgy

Forest Accumulator

Ten years ago, this would have been a speculative design project by Sascha Pohflepp: “hyper-accumulating” plants are being used to concentrate, and thus “mine,” valuable metals from soil.

[Image: Nickel-rich sap; photo by Antony van der Ent, courtesy New York Times.]

“With roots that act practically like magnets, these organisms—about 700 are known—flourish in metal-rich soils that make hundreds of thousands of other plant species flee or die,” the New York Times reported last week. “Slicing open one of these trees or running the leaves of its bush cousin through a peanut press produces a sap that oozes a neon blue-green. This ‘juice’ is actually one-quarter nickel, far more concentrated than the ore feeding the world’s nickel smelters.”

A while back, I went on a road-trip with Edible Geography to visit some maple syrup farms north of where we lived at the time, in New York City. The woods all around us were tubed together in a huge, tree-spanning network—“forest hydraulics,” as Edible Geography phrased it at the time—as the trees’ valuable liquid slowly flowed toward a pumping station in the center of the forest.

It was part labyrinth, part spiderweb, a kind of semi-automated tree-machine at odds with the image of nature with which most maple syrup is sold.

[Images: Photos by BLDGBLOG.]

Imagining a similar landscape, but one designed as a kind of botanical mine—a forest accumulator, metallurgical druidry—is incredible.

And it’s not even a modern idea, as the New York Times points out. For all its apparent, 21st-century sci-fi, the idea of harvesting metal from plants is at least half a millennium old: “The father of modern mineral smelting, Georgius Agricola, saw this potential 500 years ago. He smelted plants in his free time. If you knew what to look for in a leaf, he wrote in the 16th century, you could deduce which metals lay in the ground below.”

This brings to mind an older post here about detection landscapes, or landscapes—yards, meadows, gardens, forests—deliberately planted with species that can indicate what is in the soil beneath them.

In the specific case of that post, this had archaeological value, allowing researchers to find abandoned Viking settlements in Greenland based on slight chemical changes that have affected which plants are able to thrive. Certain patches of flower, for example, act as archaeological indicator species, marking the locations of lost settlements.

In any case, my point is simply that vegetation can be read, or treated as a sign to be interpreted, whether by indicating the presence of archaeological ruins or by revealing the potential market-value of a site’s subterranean metal content.

Indeed, we read, “This vegetation could be the world’s most efficient, solar-powered mineral smelters,” with “the additional value of enabling areas with toxic soils to be made productive. Smallholding farmers could grow on metal-rich soils, and mining companies might use these plants to clean up their former mines and waste and even collect some revenue.” That is, you could filter and clean contaminated soils by drawing heavy-metal pollutants out of the ground, producing saps that are later harvested.

Fast-forward ten years: it’s 2030 and landscape architecture studios around the world are filled with speculative metal-harvesting plant designs—contaminated landscapes laced with gardens of hardy, sap-producing trees—even as industrial behemoths, like Rio Tinto and Barrick Gold, are breeding proprietary tree species in top-secret labs, genetically modifying them to maximize metal uptake.

Weird saps accumulate in iridescent lagoons. Autumn leaves glint, literally metallic, in the sun. Tiny metal capillaries weave up the trunks of black-wooded trees, in filigrees of gold and silver. The occasional forest fire smells not of smoke, but of copper and tin. Reclaimed timber, with knots and veins partially metallized, is used as luxury flooring in suburban homes.

Read more at the New York Times.

(Thanks to Wayne Chambliss for the tip!)

London Bells / Urban Instruments

[Image: Outside the Whitechapel Bell Foundry, London; all photos by BLDGBLOG].

Before leaving London last week, I learned that the Whitechapel Bell Foundry was offering walk-in tours for the duration of the Olympics, so Nicola Twilley and I headed out to see—and hear—what was on offer.

[Image: Inside the Whitechapel Bell Foundry].

I’d say, first off, that the tour is well worth it and that everyone on hand to help us along on the self-guided tour seemed genuinely pleased to have members of the public coming through. Second of all, if you have any interest at all in the relationship between cities and acoustics—say, the influence of bells on neighborhood identity or the subtle differences in city soundscapes based on different profiles moulded into church bells—then it’s a fabulous way to spend the afternoon.

We were there for nearly two hours, but I still felt like we were rushing.

[Image: Bell-making tools at the Whitechapel Bell Foundry].

In any case, the Foundry bills itself, and is apparently recognized by the Guinness Book of World Records, as the oldest manufacturing company in Britain. They made Big Ben; they forged the first Liberty Bell; they created, albeit off-site, the absolutely massive 23-ton 2012 Olympic Bell; and, among thousands of other, less well-known projects, they even made the famed Bow bells whose ringing defines London’s Cockney stomping ground.

[Image: The ingredients of loam].

The self-guided tour took us from buckets of loam, used to shape the earthen moulds into which “bell metal” (an alloy of copper and tin) is later poured during casting, all the way to the mind-blowing final sight and sound of the bell-tuning station.

Here are some quick photos, then I’ll come back to the tuning process.

[Images: Interior of the Foundry, plus some of the casting/pouring equipment. In the bottom two images, the frames visible on the back wall were used to cast, from left to right, Big Ben; the original Liberty Bell; the Bow bells; the enormous 2012 Olympic Bell; and another bell, on the far right, that I unfortunately don’t remember].

The next sequence shows the casting of hand bells. We were basically in the right place at the right time to see this process, as the gentleman pictured—whose denim vest had written on it in black marker, “I’m not mad, I’m mental, HA! HA! HA!”—pulled apart the suitcase-like casting frame seen in these photos to reveal gorgeously bright golden bells sitting silently inside.

Using powder, almost like something you’d use to sugar a cake, and an air-hose, he removed the bells from their loamy matrix and got the frame ready for another use.

[Image: The bells are revealed and powdered].

The whole thing was a kind of infernal combination of kilns and liquid metal, soundtracked by the sharp metallic ring of bells resonating in the background.

As the origin site for urban instruments—acoustic ornaments worn by the city’s architecture to supply a clockwork soundtrack that bangs and echoes over rooftops—the Foundry had the strange feel of being both an antique crafts workshop of endangered expertise (kept afloat almost entirely by commissions from churches) and a place of stunning, almost futuristic, design foresight.

In other words, the acoustic design of the city—something that isn’t even on the agenda of architecture schools today, considered, I suppose, too hard to model with Rhino—was taking place right there, and had been for centuries, in the form of vast ovens and casting frames out of which emerge the instruments—shining bells—that so resonantly redefine the experience of the modern metropolis.

So that brings us to the final stage of the Foundry tour, which was the tuning station.

[Images: Tuning a bell; note the shining flecks of metal on the floor, which have been scraped out of the bell in order to tune it. “Tuning” is thus a kind of mass reduction, or reductive sculpting].

Assuming I remembered this correctly, modern bells are tuned by having tiny bits of metal—mere flecks at a time—scraped or cut away from the inside. This produces an incredible texture of bright, polished grooves incised directly, even violently, into the metal; the visual effect is absolutely magical.

[Image: The grooved interior of a recently tuned bell; in the bottom image, note the word “tenor” written on the bell’s inner rim].

Even better, while these massive bells are rotating anti-clockwise on their turning plates, having their insides scraped away, they are actually ringing!

Deep below the abrasive droning roar of the bell turning you can make out the resonant tone of the bell itself. The effect was like listening to tuned rocks falling endlessly in a tumbler, polished into acoustically more beautiful versions of themselves. This process alone could make a new instrument: a full orchestra of bell-tuning stations, as if mining shaped metals for their sounds.

Finally, then, the tuning process is controlled by one of three ways, often used in combination. One uses software; you bang the bell with a mallet and the software tells you if it’s resonating at the right frequencies. The second method uses an oscilloscope, which looks like something straight out of a 1980s submarine-warfare movie.

[Image: As if looking for ghosts inside the bell, the oscilloscope spins and glows].

And the third is much more analogue, relying entirely on the tuner’s own sense of pitch and the use of tuning forks.

[Image: Tuning forks at the Whitechapel Bell Foundry].

At the risk of going on too long about this, there really was something almost indescribably beautiful about the tuning process: watching, and listening to, otherwise featureless metal surfaces be sculpted and inscribed from inside by an anti-clockwise machine as the weird circular howl of the bell grew gradually more distinct, more precisely pitched with every scraping away of unpolished metal.

Being, as you’ll know by now, prone to clichés, I can’t help but think of William Blake’s “Satanic Mills” of the Industrial Revolution every time I enter an industrial facility these days, and a vision of some titanic factory somewhere in the pollution of a future era, spinning raw metal into bells, golden and shrieking things droning as if enspirited or possessed, is almost too fantastical to contemplate.

Anyway, the Whitechapel Bell Foundry is open for walk-in tours, for £10 per adult, until the end of the 2012 Olympics, after which the tours go back to advance reservations only (and the ticket price goes up to £12). Enjoy!