There was a big blackboard on which a teacher in a queer costume was writing some math problems. The class was sitting on stiff boards with no backs and as soon as one person moved the teacher was there on top of the student hitting him with a scale (draftsmen). Then the students together revolted against the teacher and they turned the room upside down, but they never touched the teacher. Then the teacher stopped and with a low voice said please be quiet (I think) and everything was the same again with the room back in order.