Wandering on a winter's night in Beijing

Stone walls may not a prison make, nor iron bars a cage, but even old Lovelace, who seems to have been able to conjure up a view for a room without any pleasant prospects, would have been hard-pressed to imagine acrobatic angels cavorting among the clouds if he'd been shut in the dungeon of murk that closed in over Beijing recently.

That's because he'd have found it hard to recall what the sky looked like after a day or two.

You could almost hear millions of people exhale a collective sigh of relief when the wind started to spoon the soup away.