Thomas Hornsby, the Savilian Professor of Astronomy, was lying on his sick-bed in the Radcliffe Infirmary when he observed a small black disk transiting the face of the sun. It was the planet Venus. The year was 1769.

This was a rare and momentous astronomical event. More than that, it was a phenomenon of worldwide significance – Captain Cook among others was inspired to make his expedition to Tahiti in order to observe it more clearly – because it had profound implications for the precise location of Earth’s position in the solar system (and the pinpointing of Longitude).

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Closer to home, and closer to the infirmary, it inspired the building of one of Oxford‘s finest, most distinctive and best-loved buildings – the Radcliffe Observatory, named after its benefactor, the royal physician Dr John Radcliffe (1652-1714) a statue of whom stands proudly on the front lawn.

The Observatory’s foundations were laid in 1772 and it was completed in 1794. Its chief architect was James Wyatt (who took over from Henry Keene), and its distinctive octagonal design was based on the ancient Hellenistic Tower of the Winds, an inspiring illustration of which had appeared in Stuart & Revett’s Antiquities of Athens published in 1762.

Inside the body of the building there are five spacious rooms, ranged over three floors, connected by a handsome circular staircase. And in the viewing chamber itself, at the top, is displayed an antique telescope (donated by the seventh Duke of Marlborough, Winston Churchill’s grandfather) as a reminder of the building’s original purpose.

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The Atlas and Hercules-borne globe which tops the roof seems to bobble mysteriously on the skyline. You get magical glimpses of it from across Port Meadow, peeping through gaps in the houses along Plantation Road, or hovering over the streets of Jericho. And with the opening up of the Radcliffe Infirmary site you can now walk up close and admire the fine shape of the building and the inlaid plaques of coade stone embellished with signs of the zodiac. The crab of Cancer is especially distinctive.

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It reminds us of Oxford’s scientific contribution and expansive vision. A world encompassed. A universe even. Reminds us also of our cloudy weather system and low-lying setting. For, after a couple of attempts to re-establish it in the Science Parks, all but one of the telescopes was relocated in 1935 to South Africa, where the skies are distinctly less murky. The upshot is that these days the Radcliffe Observatory is more observed than observing – but no less celestial for that.

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For a long time the Observatory must have been the most distinctive building in North Oxford, visible for miles around, especially from Jericho. Oxford architect Ray Foulk laments the views we have lost.

At one time the most delightful vista in Jericho would have been that from Cardigan Street, with the imposing clocktower of St Barnabas at one end, and the Observatory at the other.

Sadly, the vista in both directions has since been largely blocked and ruined by the primary school (1977) which cuts the street in two. Prior to this, and the placing of a plethora of buildings at the back of the old Radcliffe Infirmary, the sight-lines in both directions were indeed special.

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Incidentally, the Observatory tower, which is now largely blocked by the modern buildings in Little Clarendon Street would once have appeared plumb centre from St John Street. When St John Street was being laid out, it is possible that its precise orientation, given that it was a prestige address, might have been determined by the tower ahead. Well, possibly … (The top of the tower is still visible from St John Street, dead centre in the distance.)

A Fellow of Green Templeton college writes to correct our romantic but erroneous opening sentence.

It’s a nice story about Hornsby in his sick bed – but the infirmary was not in fact open to patients until 1770. No: the roof of the unfinished building was used by Hornsby for planned observations, simply because it was higher up and out of the centre of Oxford.

Talking of celestial movements, Lee Macdonald is a keen observer of the night sky. He took this dramatic photograph of another (partial) solar eclipse from the pavement outside the Weston Library, over the road from his workplace at the History of Science Museum. It is dated 25 October 2022, 09.54 GMT.
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This magnificent graffiti which adorns the wall of Green Templeton College takes its inspiration from the globe which tops the nearby Observatory. Our thanks to Daniel Evans for the photograph.
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Bob Carr sent in this view of the Observatory, a vista which is fast disappearing behind the Stephen A. Schwarzman Centre for the Humanities.
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None other than the former Principal of Green Templeton College, Colin Bundy, was moved to respond to our piece on the Radcliffe Observatory.

I much enjoyed your appreciative account of the Observatory. It is in so many ways a building of the Enlightenment – built when it was, as a place of science, and its architecture so elegant, harmonious and optimistic. You may well already know about the sundial, but I am sending this link in case you don’t:

The Observatory also has a fascinating and unexpected history in the years between the relocation of its astronomical functions and its being the centre of a new college in the 1980s. Some of my older medical colleagues regaled me with tales of its use in the 1950s and 1960s as an ad hoc research centre. These included the story of (1) getting a sword-swallower from St Giles Fair and x-raying his throat muscles while he dutifully swallowed a sword; and (2) the neo-natal study which used sheep as subjects (which meant herding pregnant ewes up that spiral staircase to the first floor.) There are several other similarly unlikely episodes …

When David Attenborough did a big BBC programme on climate change, in 2007 or 2008, he began it standing next to the little weather station on the lawn; for the Radcliffe Observatory has yielded the longest unbroken daily weather record in the UK – a record which, as I enjoy telling American visitors, began during the American revolutionary wars. CB

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