The position of Ron's umbrella while talking to Marissa outside the state building.
When Mr. Clark was teaching grammar he asked one of the students to keep watch on the time and let him know by banging a candy jar every 15 seconds with a ruler. When Mr Clark handed the child the jar it was full of candy. When the lesson was over the student returned the jar it was completely empty. There was no way one child could have kept time as requested by the teacher and eat the candy.