IN FEBRUARY 2012, with a subzero front from the Urals hanging over central Europe for two weeks in a row, Strasbourg’s canals froze over, a phenomenon I had observed only once before in twenty years. Instead of the smoothly scored patinoir surface you see on Brueghel’s famous painting when the whole village goes out to the frozen pond for a rare hour of winter amusement – an event I enjoyed many years ago in a Bavarian village when the scene was so reminiscent of Breughel’s painting that I dreamt I was living in the sixteenth century that night – the surface of the normally placid canals had been ruffled by the easterlies even as they froze and taken on brashly agonal postures. Ice can be a dramatically sculptural substantiation of its liquid medium. Over the next few days the jaggedness was exaggerated by the tug which forced its way around the city to break the ice and ensure at least a few hours’ open transit on the Rhone-to-Rhine canal for the occasional barge – as well as for the swans, which gathered at night in tight dark pools close to the bank where the water was warm enough to be still lapping at the quay. Venturing along the canal path to the big multiplex cinema on the reclaimed docklands across from what used to be one of Vauban’s splendid star-shaped defences of the city, the eerie moonlit stillness of the scene reminded me strongly of Caspar David Friedrich’s compelling paintings.