Why did we pull on national colours for the Blue Rigi?

The spirit of British patriotism, a discreet, almost subliminal presence in everyday existence, is a powerful enough force when prodded from its gentle slumber. It's not done to fly the flag, or suggest that Britain's greatness lies in anything other than its self-effacement ("valuing dysfunction" should perhaps be our national mission statement). But try to mess with a Briton's right to hang British art in Britain, and the country's slumbering self-love erupts with a force of feeling sufficient to rival that of any Marseillaise-singing Frenchman.

Hence the delight that greeted yesterday's announcement that Turner's celebrated watercolour The Blue Rigi has been saved from the perils of foreign travel. Within five weeks of the government deferring the export licence, funds to the tune of nearly £5m were raised, more than £500,000 coming directly from the public following the Art Fund's "buy a brushstroke" campaign. (In truth you'd find this rather difficult - the pixels on sale at £5 a pop are considerably coarser than the fine strokes of Turner's brush.)...