Before Professor Herbert meets Mr. Sexton, what is your impression of the teacher?

In the beginning of the story, Professor Herbert tells Dave that he must pay his part of the six-dollar fine for breaking down the cherry tree. Dave protests that he doesn't have the dollar and begs his teacher to whip him instead.
Upon hearing this, Professor Herbert answers that Dave is too big to whip. Professor Herbert doesn't appear to be the sort of teacher who automatically resorts to capital punishment when his students misbehave. Instead, he gives the impression that he is fair yet uncompromising in his values. His fairness and compassion are demonstrated when he declines to whip Dave and offers to pay his student's fine.
Next, Professor Herbert orders Dave to work two hours after school for two consecutive days in order to pay off his fine. He tells Dave that he can do various chores such as sweeping the schoolhouse floor, cleaning the windows, and washing the blackboards. In this way, Professor Herbert is able to help Dave and to hold him accountable for his part in breaking down the cherry tree.