How do the boys get revenge on Mr. Dobbins?

Answer 1

• The boys and girls decide to get back at Mr. Dobbins with a prank, and they enlist the sign-painter's boy to help…but more on that later.
• On the evening of exams, each student takes his or her turn reciting some kind of speech. Tom does Patrick Henry's "Give me liberty or give me death" speech, but he loses track halfway through has to give up.
• Most of the chapter is given over to a number of bad poems and orations, most of them given by the female students. These need not be covered in detail. Just remember, they're all pretty horrid and florid.
• When all the speechifying ends, the fun begins. As Dobbins is drawing a map of the United States on the blackboard, one of the boys lowers a cat from the ceiling; said cat grabs onto the schoolmaster's wig, revealing his bald head…which has, somehow, been gilded by the sign-painter's boy.
• The boys get their revenge, and school's out for summer.

Answer 2

The boys get revenge on Mr. Dobbins by locking him in his own school and painting his face with black ink to mimic a black face. This prank humiliates Mr. Dobbins and causes him to lose his authority over the students.