the frosting of winter lawns

It was spectacularly cold and frosty this morning: I bundled up to take these pictures (and then go and fetch the newspaper).  Later, I bought my father his (early but necessary) Christmas present: a luxuriously thick goosedown duvet.  He's been a lifelong spurner of duvets, but thinks that the moment may have come.  The blankets on the bed date, after all, from the 1950s (and are still there, of course, supplementing the duvet).  It's down to 27 already tonight - which in a house with bad insulation (that's an understatement) is chilly.