Snow on the downtown cobblestones is beautiful for roughly an hour, and after that it is a problem. Lemieux Tree Service handles the practical half — plowing lots, shoveling walks and doorways, salting the stone and concrete where a thaw refreezes into glass. New Bedford storms blow in heavy off the water and rarely stay tidy, so the work runs through the night and on into the gray of the morning. A path opened wide and gritted properly can be the difference between a door that opens and one that stays shut. Clean pavement before the city wakes up is a good way to spend a winter.