"Why, the tracks will be plainer in the snow," said Nat.  "And we can slide down hill, too, after we find the chair and take Grandma's glasses back to her.  Let's run!  I can see where the chair has been along here," and he pointed to the marks in the soft ground--marks that looked as if a two-wheeled cart had been hauled along there. They were the tracks of Racky's rockers, plain enough.