The world's biggest small mystery

The museum world is a tiny place with gigantic ideas. Four years ago, in 2012, to understand how the Thomson Collection of European Art's miniature carved boxwood prayer beads at the Art Gallery of Ontario were made – a mystery that has defied human understanding for more than 500 years – curator Alexandra Suda and conservator Lisa Ellis took the radical step of radiating one of the pieces in an $800,000 micro-CT scanner. CT scanners X-ray infinitesimally thin slices of an object and then add them up; they're good at revealing hidden interiors.

The results were so astounding that Suda and Ellis called Barbara Drake Boehm, a renowned curator and medievalist at the even more renowned Metropolitan Museum of Art in New York, and Pete Dandridge, the Met's chief conservator. Boehm had hired Suda as a graduate student in New York and subsequently urged her to take a job at the AGO, partly to find out what medieval treasures the relatively unknown Thomson Collection – in Toronto, of all places! – had in its clutches. After then approaching Frits Scholten, Europe's top boxwood-sculpture man at the famous Rijksmuseum in Amsterdam, the fivesome started hatching plans.

The final result is an international exhibition, Small Wonders: Gothic Boxwood Miniatures, that premieres Saturday in Toronto at the AGO, and then travels to the Metropolitan Museum of Art and the Rijksmuseum. Toronto's boxwood has hit the big time, baby.

But the discoveries relate to much more than technique. In an ever-more virtual world awash in technology and information, at a time when machines are increasingly more capable than humans, the show raises profound questions about ancient objects that, it turns out, can be made by human hands alone – treasures we can see and contemplate and touch, but never completely understand, exactly as their makers intended. That might be a big idea.

'The Rolex watches of the Middle Ages'

Only 135 miniature boxwood carvings – prayer beads and miniature altarpieces included – survive to this day. Twelve of the world's extant prayer beads are in the Thomson Collection at the AGO. They were designed to be worn as devotional objects at the end of a rosary a Catholic would use to count off prayers: The spheres open to reveal two or more religious scenes from the Bible. But they were equally important as status objects – "the Rolex watches of the Middle Ages," according to Scholten, who was in Toronto this week to see the set-up of the exhibition. The original beads were carved between 1500 and 1530: After that, they simply disappear, possibly due to the no-nonsense Reformation (which disapproved of religious tchotchkes) or maybe because the man who made most of them had died. There is general consensus most were made in Antwerp, in Flanders; less consensus that they were made in one or two workshops; and less consensus still that both workshops were run by a guy named Adam Theodorici.

Woodcarvers' special bond with boxwood

Boxwood was prized, and not just by carvers: It was used (with a little cabbage added) to dye hair blond as early as the 11th century, and was traded internationally between Europe and the Middle East, along with camel hair and lapis lazuli. Hollowed-out boxwood spheres were even the subject of a trade dispute between the Netherlands and Britain. (Some things never change.) Craftsmen used tiny five-centimetre-long tools to drill and gouge and vein the exquisitely detailed religious scenes within the beads – some of which depict dozens of characters in full regalia and action, in a space about 2.5 centimetres wide and 1.5 cm deep. But the carvers had a special attachment to boxwood: It had a consistent grain, was hard enough to hold its shape and was thought to have been one of the woods used to make Christ's cross.

Micro-CT scans expose long-hidden secrets

How did the carvers work so much unbelievable detail into such deeply layered scenes in such tiny spaces? The AGO's micro-CT scans reveal for the first time that they were carved from a single piece of boxwood, but in parts, like stage sets, then held together, grain aligned, with tiny boxwood pins smaller than a single grass seed. "They would overlap each disc onto one another after they'd been carved to get this sort of extraordinary sense of relief, depth," Pete Dandridge, the Met conservator, explains. When the show's curators asked Mark Paddison, a master carver from Toronto with 30 years experience, to recreate a prayer bead by hand a year ago, he could manage only the outer casing, which took him a week to make, even by machine, and then only in maple: Boxwood was too hard. "It's like drilling out concrete," Paddison says.

A year ago, with an early CT scan as a guide, Dandridge took a 500-year-old prayer bead apart, by hand, very carefully. (They tend to sell at auction these days for about £140,000, or roughly $230,000.) "There was no way I would have ever contemplated taking them apart without that information," he says. "I literally looked at it for six months, waiting for that point at which I was comfortable with taking that first step."

The facing scenes inside the beads often divided into good news and bad. One half of the bead Suda and Ellis first scanned depicts heaven above purgatory, and purgatory above the mouth of hell. Down is where you're going if you're bad. The other half of the bead celebrates the Annunciation of the Virgin, the moment Mary discovers she's pregnant with God's son. (Visitors can experience an enlarged 3-D virtual-reality tour of this bead in the AGO show.) The tiny (four millimetres high), almost invisible man caught in the mouth of hell is an insert (Lisa Ellis, the AGO conservator, speculates it's a self-portrait of the artist), as are the hard-to-see rack behind the mouth (from which two unfortunate human corpses are hanging), the starry background behind purgatory, the kneeling figures in heaven and the roof and its rays of celestial light.

'You become lost in that biblical moment'

Endless quirky details transform the otherwise well-known biblical scenes into stories George Saunders might have written. In the bead depicting heaven and hell, someone wearing a papal tiara is disappearing down the trap door of purgatory into the mouth of hell. In another bead the Met has lent to the AGO show, Pontius Pilate (having caved to public pressure to condemn Christ to death) is washing his hands, permanently, in water being poured from a ewer. He really does looks a bit like FBI director James Comey. Below him, on a step, blithely ignoring the fact that he's sitting next to both the Son of God and a monkey on a chain, a pudgy fellow adjusts his glasses to read a book. "It's self-referential," AGO curator Suda says. "An inside joke – a guy reading a book with glasses, carved by a guy with glasses holding his object at the same distance as the guy holds the book."

Every character in every scene seems to have a hat (hats were hip in Western Europe in the early 1500s); each one is fabulous in its own way, dented or banded or buttoned or tasselled. Shields, bridles, saddles, tethers, caged (but moving) pigeons, banderoles, the odd wheelbarrow, spears, faceted spears … all abound. A sponge of vinegar held at spear-length to the mouth of Christ on the cross bears tiny sponge holes. "It's a question of the detail," Barbara Drake Boehm points out. "I think it feeds that contemplative aspect. You become lost in that biblical moment. You can do narrative big. But when it's really tiny like this you go privately into that place. You travel there." Time, man's enemy, is stopped in its tracks.

Until Suda and Ellis designed the AGO show, it was impossible to see with the naked eye all that's going on in the prayer beads, even with magnification. (Eyeglasses originated in Venice at the end of the 13th century, but as late as the mid-1600s offered no better than 2X magnification.) This peekaboo quality of the beads seems to have been intentional. The paternoster (the main prayer bead) of the famous Chatsworth House rosary that once belonged to Henry VIII and Catherine of Aragon (one of the centrepieces of the AGO exhibition, it was likely given to Catherine and Henry as a wedding present in 1509; she seems to have kept it after their long-awaited divorce) depicts Henry and Catherine attending mass. But until the CT scan revealed them, they were hidden behind a pillar. Similarly, a teeny rack of flayed and bleeding humans is only partially visible behind the fierce but tiny mouth of hell. (The mouth looks – no exaggeration – a bit like Donald Trump.) "They are endlessly frustrating, because you can't see," Suda says. "But then, you can't see God. And there's an artistic tradition of that. What I can't see is what I have to believe."

'Even with the scanning, I know nothing'

Because the beads couldn't be fully seen, they couldn't be studied, which is why they have been mostly overlooked in the narrative history of Western art.

To overcome the problem, AGO technicians photographed each prayer bead at 60 fractionally different focal lengths. Those images were then stacked into a single digital image in perfect focus. The composites have been massively enlarged and mounted on the walls of the exhibition. (Another project, to create a prayer bead on a 3-D printer, produced nowhere near the detail in the original carvings: "They kept saying, wait another six months, the technology will be even better," Suda remembers. "And yet after five years, the art is still ahead of the technology. I find that ironic.")

The decision to blow up the details of the prayer beads was heavily debated. Ellis and Suda worried they might somehow betray the intentions of the artist(s) who made the prayer beads so hard to fathom. But the beads are holding on to their secrets anyway. Who made them? Why? How long did they take? How much did they cost? Who invented them in the first place? All these questions are still unanswered. Suda now admits she needn't have worried. "When I feel guilty about compromising the artist's technique, I realize that even with the scanning, I know nothing."

Ken Thomson and the birth of a collection

The fact that the AGO has the world's largest collection of miniature carved boxwood prayer beads gave it a leg up in the horse-trading that went on (as it always does) in the lead-up to the exhibition. Each visiting boxwood carving arrives with a minder-curator from the contributing collection, who guarantees its safe passage and careful display. Henry VIII's bead is insured for its stay in Toronto, though like everything else at Chatsworth House (the palatial Derbyshire seat of the Dukes of Devonshire), it's too valuable to be insured when it's at home. Each lender has particular rules: The British Museum famously insists on bulletproof glass cases.

The AGO's collection was bequeathed by the late businessman and philanthropist Ken Thomson; his passion is still shared by his son David (whose family holding company, Woodbridge, owns The Globe and Mail). Unlike many other collectors of prayer beads (the Rothschilds, J. Pierpont Morgan), Ken Thomson began collecting modestly in 1953, when he was in his 30s, long before he was a billionaire. His first purchase – for less than the £30 the dealer was asking – was two small ivory busts made by the Victorian sculptor Benjamin Cheverton on a modified pantograph, a device that allowed Cheverton to cheaply reproduce small-scale imitations of larger, more famous originals.

They kicked off what today is the world's most extensive private collection of ivory and boxwood carvings. "They feel good … not only through the eye, but through the touch," Thomson once said. He was known occasionally to carry a boxwood bead in his coat pocket, so that interested visitors could experience the thrill of holding one. "Isn't it funny," Suda asks, "that the first reaction people have today, looking at the beads, is probably the exact same first reaction people had when they looked at them in 1520?" You can't stop looking at them. Why?

Objects offering finite scenes, but infinite wonder

Museums conduct endless visitor research to find out what gallery-goers like to look at, and what they might therefore pay to see. The answer – which could be a self-fulfilling prophecy – is usually modern and contemporary art. Two years ago, some 200,000 visitors to the AGO saw the extravagantly promoted art of Michel Basquiat, a Warhol protégé. The advertising budget of the boxwood-carvings show, despite huge international collaboration, could afford a few online ads.

The rationale is straightforward: What relevance can historical and religious art possibly have for people today?

It's an interesting question. One day last spring, I spent two hours with Barbara Boehm, Pete Dandridge and Lisa Ellis, happily gazing through loupes and magnifiers at three of the prayer beads in the Met's collection.

Eventually I had to leave. I thanked my hosts and turned south down Fifth Avenue, and then right again into Central Park.

It was a gorgeous spring day: Everything was blooming. I could see 20 people strolling through the park at a single glance. Having just spent two hours peering at objects that could fit in the palm of my hand, I was surprised that every single passerby was gazing into his or her hands as well.

They, of course, were looking at their cellphones.

The information on a cellphone, our most common modern devotional object, changes incessantly. There is no end or bottom to where it can lead you, hence its seductive brilliance (the average person spends 90 minutes a day looking at their phone), and why it can make you antsy: When you can go anywhere via hand-held technology you can carry in your pocket, there is no end of places you ought to be, no end to what you might be missing. We devote our attention to change. Our smartphones are the headstones of that addiction.

A prayer bead carved in boxwood, on the other hand, contains a finite amount of information. Its scenes never change. The crusader on a bridled horse chasing an infidel on a camel has been doing that and that alone for 500 years.

But the wood waits for us to find its crannied details, so we feel we're in control of the discovery. The amount of information we take in is limited only by our own curiosity, by what we make of it, rather than what it makes of us. The cellphone forces us to keep up to its pace; the prayer beads ask us to slow down, and reward patience every time someone looks and marvels. They make a radical suggestion: Maybe we're paying attention to the wrong things.

Small Wonders: Gothic Boxwood Miniatures runs from Nov. 5 to Jan. 22 at the Art Gallery of Ontario in Toronto (ago.net).