The sundial designer putting a modern twist on ancient technology

It was only a matter of time until Chankillo in Peru was identified as a solar observatory. The 2,300-year-old desert monument looks like the arched back of a partly submerged crocodile, with 12 gaps between its 13 spinal blocks. The sun would rise within one gap each month as the earth shifted in the heavens, the great clock perhaps marking festivals or planting. We have always needed to tell the time, even if none of us really knows what time is.

This South American Stonehenge adds to the long roll-call of ancient sites given to mapping the year by charting the sun. It is second nature to glance at a wristwatch today, but after centuries of refining and perfecting portable timepieces the natural simplicity of casting solar light or shade remains beguiling, and sundials frequently feature in the show gardens at Chelsea Flower Show.

Sundial designer and sculptor David Harber from Oxfordshire is collaborating with celebrated garden designer Nic Howard for a second year, and will showcase his two latest sculptures, The Eclipse and The Quiver, on his Main Avenue stand at Chelsea.

Harber insists that he didn’t set out to be a craftsman of chronometry. “Until about 25 years ago, I had no notable interest in sundials. Then I saw one and immediately developed an obsession,” he says. Perhaps it was written in the stars, for one of his ancestors, John Blagrave, was an Elizabethan mathematician and scientific instrument maker who spent most of his life just 20 miles from where Harber’s Oxfordshire workshop is now.

“When I first started making sundials, I used the metalworking skills I developed when converting a 120-tonne 1920s cargo boat into a travelling theatre,” he says. Harber is the first to admit his early commissions were a bit rough and ready. Now, a team of 18 talented craftspeople makes the company’s pieces to the finest of standards, using exceptional materials. These include Cor-Ten (panels of marine-grade steel with a rusty surface like russet suede), bronze, stones of various sorts and glass. All use a variety of craft techniques — cutting, casting, folding, bending, heating, hammering — to yield the finished effect. “With our bronze verdigris pieces, we apply specially formulated acid solutions by hand to expedite the ageing process — giving natural weathering a 20-year head start,” Harber explains.

The ageing process will inevitably take its own course, and Harber says clients often seek legacy pieces. “Many of our clients personalise their commissions with engravings — names, dates, longitude-latitude coordinates, quotes or even words written by their children, that we can scan and etch on to their piece. This makes for a powerful family heirloom — the scribbles of a five-year-old can be read by their great-great-grandchildren.”

Sundials, then, are opportunities for a childhood to cheat time, even through a mechanism that charts its evolution into adulthood, and beyond.

At its simplest, a sundial can be a stick shoved in a hole in a wall, its shadow arcing past radial scratches in the masonry. These scratch or mass dials can be seen on medieval churches, when people reckoned time by measuring their own shadow between 1ft and 29ft, according to seasonal tables.

Such simple techniques presumably existed before the basic sundial emerged as a Babylonian concept about 2,500 years ago — Chankillo’s time — using a vertical gnomon. By about 30BC, Vitruvius, the Roman architect, engin­eer and writer, was bemoaning that solar dials were so sophisticated and various that there was nothing new under the sun for them.

Harber begs to differ. “I was once approached by a client for a very modest sundial, and after a very long pub lunch, we ended up creating a gigantic solar system model, which comprised a whopping 200 tonnes of stone,” he says.

There is every opportunity for variety when the design process is a conversation between the design team, the client and Harber himself. “We need to first understand the person, their likes and dislikes, and the site on which the piece will eventually sit,” he says. “We go through a journey with clients to either design something entirely bespoke for them, or adapt and evolve one of the pieces from our range.”

The most complex rendering of sundials are armillary spheres. These are open metal globes whose bands are inscribed with measurements. None of this should prove daunting. Fifty years ago, an American writer, Albert Waugh, suggested the amateur artisan could create an armillary sphere “three or four feet in diameter by welding together the metal tires of old wagon wheels”.

There is a place for rough and ready, but there will always remain a market for the best-quality work — pieces that, left in the elements, will still be standing in 500 years’ time. Harber enjoys meeting the survivors. “In the very early days of my fascination with sundials, I restored a 500-year-old piece, and as I polished the bronze, the maker’s signature was revealed,” he says. “I was incredibly humbled to think that I was the first person to see that script for a very long time.”

Britain’s earliest portable sundial is at Canterbury Cathedral, a 10th-century silver pendant obelisk with pegs set into sockets according to the month. In the west, the great churches as celebrants of the heavens through regular services were innovators in timepieces, and eight centuries ago moved from sundials toward iron-framed clocks such as that at Wells Cathedral. The age of exploration brought watches; the modern scientific age gave us quartz movements and the atomic clock. Can the ancient technology of sundials ensure accuracy?

“We always set our sundials to Greenwich Mean Time,” Harber says. “Over time, politics may change the notions of British Summer Time and daylight saving time, but GMT is the internationally, historically recognised standard — Greenwich is the home of time and navigation. Politics can never change the objectivity of the earth’s orbit around the sun.”

So there, if you understand that Harber’s sundials refer to GMT year-round, they’re accurate enough — when the sun’s out. After all, most gardeners wear watches. They just don’t look as good as casting sculpted shadows on long summer days.

Photographs: Howard Sooley; David Harber