The eclipse-watcher's greatest enemy is cloud. Even though science can predict the precise moment and location of an eclipse several millennia in advance, the weather remains an unpredictable element of sabotage. High cirrus cloud - no problem. Thin altostratus - fine. But lumpen grey stratus, sorry, spectacle denied.
Tuesday morning, and twenty-or-so eclipse-watchers assemble atop Primrose Hill. This is the highest point of land close to Central London with a southeastern view, so it's a good place to be. The time's around eight o'clock, a few minutes before sunrise. Most of the sky is obscured, but miraculously there's a narrow slit of shady light illuminating the horizon. It's not certain, but it looks like the cloud might be thin enough to allow at least some solar light through. Ah no, false alarm. A curtain of grey descends, the imminent sunrise is shrouded, and the moment is lost.
In a city of eight million, I'm distinctly unimpressed by the tiny audience at this prime viewing spot. But the few who've made the effort are here in the hope of seeing something spectacular. Some are optimists, who've heard the weather is supposed to be rubbish but have come up anyway. Some are merely passing through with dogs to walk, and have paused on the summit to see what's going on. Two are professional photographers with giant-lensed cameras, hoping to sell photographs of amber crescents to news-gathering organisations. Others have heard something about an eclipse, maybe on the TV or on the internet somewhere, but haven't quite grasped the scientific details of what's to come. In the absence of any solar activity, it's this latter category who are the most interesting to watch.
» Two parents have brought their young daughters up the hill to see whatever it is they're going to see. They stand at the top of the slope, point towards Canary Wharf and wait. Absolutely nothing happens. This is because there's still one minute to sunrise, but they don't know that so they give up and walk away. » Another pair of skywatchers give up two minutes later. They've heard the eclipse is supposed to be at sunrise, but haven't grasped the concept that it lasts much longer than that, so they turn to each other disappointed and wander off. » Four lads in hoodies come and sit on the bench because one of them heard about the eclipse on the radio. They stare at the Post Office Tower, which is in completely the wrong direction, because the unlit horizon's not offering them any clues. They chatter, they smoke, and then they bugger off to the gym.
But there is something exceptional about this morning's sunrise. It hasn't happened. Normally by twenty past eight the sky over London would be brightening fast, even on an overcast day like this. Not today. The streetlamps scattered across the foot of the hill are still burning orange. The sky remains a dim pre-dawn grey. And all because two-thirds of the Sun is missing. More importantly, it's the top half of the Sun that's had the biggest chunk bitten out by the Moon's shadow. The remaining exposed yellow crescent is lower on the horizon, so has yet to shine down on the cloudtops and illuminate London's morning. If you know and understand what's happening, it's oddly eerie. But almost nobody in the capital has spotted that sunrise has been delayed. They probably just think it's still dark, or foggy, or more likely aren't thinking about light levels at all.
The professional photographers remain on the hilltop longer than most, but leave without taking a single frame. Eventually it becomes obvious, even to the most stubbornly optimistic observer, that the cloud blanket won't be clearing any time soon. The eclipse still has another hour to run, but its black shadow is shrinking fast and soon won't be worth seeing even were it visible. Time to head back to normality, after a non-event caused by evil wildcard cloud. To the handful of us who noticed, another magicalastronomicalphenomenon has been wrecked by meteorology. Spectacle denied.