As they pass through the Entrance Hall, quizzical visitors to Dumfries House are often drawn to one of the estate’s most curious items: a mahogany and engraved-brass Grand Orrery. A beautiful, mechanical, heliocentric model of the solar system, it was made by Benjamin Cole of London in around 1758. “It’s a fine example of a Georgian instrument and works to this day,” says Collections Manager Thomas Breckney. “It was the boy’s toy of the Age of Enlightenment – men wanted to pretend they knew all about celestial mechanics.”

The object is named after sciences patron Charles Boyle, Earl of Orrery. The Earl had one made, which became the standard. Soon people were going to instrument makers and asking ‘Can you make me one like Orrery had?’,” says Breckney. “Eventually, it became the word for it.” It posed a few challenges when it came to its recent conservation (restoration implies making changes and replacing parts, which would erode the piece’s authenticity).

Firstly, there was the need to find an expert with the requisite skills to disassemble, clean, label, then put back together its complex array of gears, arms and winding mechanisms. Enter Michael Bennett-Levy, an expert in conserving early technology who, sadly, passed away in September. Bennett-Levy described spending an estimated 200 hours working on the piece as “a once-in-a-lifetime opportunity” and said he would have happily worked on it for free.

Meanwhile, James Hardie, who restored the wooden case in which the Grand Orrery rests, found age-related shrinkage to be a major hurdle. “The mahogany frame, that the pillars holding up the brass ring on top are screwed through, moved out of shape and had a large 20mm split. Some were pulled out of alignment with the force,” he says. “I had to graft in 250-year-old mahogany to fill the split and push the frame back into something close to a circle to put most of the pillars into the right places. It was a privilege to handle and inspect such a piece, let alone take apart and restore it,” says Hardie, “If bills didn’t have to be paid, it’s the type of thing I’d do for love, not money.”

Hardie says only around 10 of these exist in the world. The suffix ‘grand’ reflects that it depicts the outer planets as well as the sun, moon and earth. But eagle-eyed visitors may notice a few omissions, both celestial and earthly: “It’s a lovingly detailed depiction of the solar system as the Georgians understood it, because it ends at Saturn,” says Breckney. “There’s no Uranus, no Neptune, no outer planets. Also, the Pacific north-west of America is not yet fully marked and only Australia’s west coast is delineated.”

Fine dialling, planetary objects, and the Grand Orrery with its nifty travel cage, and box

Words Nick Scott

Photography Simon Brown