Flowers on the Bridge St Joseph Cupertino pray for us   At speed on the motorway I see with flickering eye, the flower-bunch tied to the bridge rail; and see it properly for the first time, where the road crosses the canyon of river-through-sandstone: far below.   But because there’s no pedestrian path on it I used to think some kind of car crash happened here; until I twig that beyond the flowers the drop is of such immediate depth that it had become one of those subtle black doors that edge the field of vision; a door without depth…