IT all began when David Harber looked inside the back of a friend's old van and noticed a somewhat battered metal object.

David remembers: "He told me it was an armillary sundial. I was exposed to it for about 30 seconds."

And he was hooked.

Now, ten years later, David is internationally recognised as a sundial- maker of extraordinary skill and imagination.

His commissions have included a sundial tower for the Millennium Dome, an armillary sphere for Wycombe Abbey School, a strip dial for Magdalene College Oxford, a mirage glass obelisk sundial for Citroen's UK HQ, an arc of monolith stone circles that tell the time on an Oxfordshire hillside, a sphere sundial at Walmer Castle to commemorate the Queen Mother's 100th birthday, and many more.

It was an unexpected career move. When David left school in Devon he became an apprentice thatcher.

"It seemed romantic," he recalls.

Then he became a potter during the week, while working at weekends as a professional rock climbing instructor with army cadets which led him to work for the BBC in Patagonia doing rock climbing camera-work.

This was then followed by a stint running a boatyard in France. For a few years he took a floating arts centre on a barge through Europe.

All these jobs were packed in before he reached 33.

"All my career moves have been maverick, unusual or hopeless," he says.

Then ten years ago he came back to England, married and had a daughter.

When divorce followed, he lived in Hambleden looking after his little girl. That's when the antiques dealer friend paid a visit.

"The next day after I set eyes on the armillary sundial I went to the Museum of the History of Science in Oxford to look at sundials. I was obviously a man on a mission and they let me open the cases to take measurements.

"Then I came home and made one on the steps of my cottage.

"I couldn't afford the rent for the end of the month. Stupidly instead of going out and getting a job I worked on the sundial, spending my last money on metal.

"But someone drove past and saw it evolving and asked if it was for sale. He gave me one month's rent. Then I made another and I never looked back."

The early years were an enormous learning curve as David delved into the history, mathematics and philosophy of early time pieces and developed technical expertise in their construction.

Now he runs a large studio in an old dairy at Valley Farm, Bix, near Henley-on-Thames with three other craftspeople, one of them an experienced engineer. Their work sells all over the world.

So why do people spend hundreds or thousands on a sundial?

David explains: "It's an unusual and romantic device. It's one thing to buy a garden bench for your home. It's quite another to have a brass armillary sundial that will last for hundreds of years. We also make them in surgical grade stainless steel which unless a bomb hits should last 1,000 years.

"They are often bought to mark anniversaries or christenings. All can be personalised with the name of the house, the date and the occasion, and any other personal inscription. One was inscribed with the client's family tree."

Other sundials are commemorative, or classy corporate dials for prestigious buildings.

David's studio now makes 20 different kinds of sundial, adding two or three new styles each year.

Sometimes they are based on ancient timepieces, others are his own bright ideas, like his Moon Dial Statue. The statue holds a ball, which is representative of the moon, in her hands, and you can move a piece of metal to chase the shadow and tell the time. It's the perfect romantic garden ornament.

His latest is a crystal orb sundial: "It's very exciting, a 150cm diameter ball on three neolithic style standing stones made of mild steel. Time is etched on the inside of the acrylic surface."

One unusual sundial is a noon cannon, a replica of one commissioned by Louis XIV.

At midday the sun's rays are focussed through a lens and heat gunpowder which fires a six-inch brass gun. Its purpose was to tell the royal gardeners it was lunchtime. David's solid bronze noon cannons are bought by people who want the ultimate big boy's toy to impress the neighbours.

But you can't walk into the studio and buy a sundial off-the-shelf. Each one has to be designed specially for the place where it will be sited, accurately aligned with its precise longitude and latitude.

Sundials can be elegant, redolent with tradition, quirky, beautiful. But there's another element to their appeal.

David explains: "A sundial holds the mystique of ancient mathematics. It's a terrestrial manifestation of the heavenly bodies.

"With the new millennium there is a revival of interest in these timeless and beautiful devices that speak to man of his place in the cosmos."

David Harber's sundials feature at an exhibition at the River & Rowing Museum, Henley-on-Thames, until April 22.