One striking incident involves the replacement P.T. teacher, Mr. Bell. In Chapter 19 of To Sir, With Love, Mr. Florian speaks with Mr. Bell about his caustic remarks to the boys about their smelly feet. While Mr. Florian does not desire to criticize his teaching, he simply asks that Mr. Bell be more understanding about the conditions in which some of the students live, conditions that do not include running water in their lodgings.
Bitter at being counseled by the headmaster, Bell takes his feelings out on his class and forces the fat Buckley to try to vault. Buckley charges the vault, but is unable to clear it; instead, despite Bell's attempt to restrain him, Buckley and the "buck" crash to the floor "with a sickening sound" as a leg snaps off sharply. Suddenly, Potter, "big, good-natured Potter" also snaps, grabbing the broken metal leg, he advances on Mr. Bell, screaming "You bloody bastard."
Fortunately, another student runs for Mr. Braithwaite, who rushes to the scene. Placing himself between the student and the teacher, Braithwaite calmly asks Potter for his weapon: "...hand it over and lend a hand with Buckley." Braithwaite also has to diffuse the anger of the boys who wish to retaliate against Bell.
Because injuries must be reported, Braithwaite is concerned that he get in the middle of hostilities with Bell. Returning to his classroom, Braithwaite scolds the boys for reacting as they did; he tells them they cannot lose their tempers at jobs or other situations in life. He tells the boys,
"The whole idea of this school is to teach you to discipline yourself. In this instance you lost your temper and behaved badly to your teacher. Do you think you are big enough to make an apology to him?"
Porter, fidgets, but agrees reluctantly. This incident has taught Porter and the others a most valuable lesson about self-control in controversial situations. It has also taught them that people who should control themselves do not always do so.
I would say that the main incident of significance in the novel is if Braithwaite will be successful in being a teacher. The conflict is between he and his students at the outset of the novel. The large issue is whether or not Braithwaite will find success as a teacher or whether this calling is right for him. It is evident at the end of the novel that the resolution calls for him to be at one with teaching and his students. Braithwaite understands that he has been able to reach his students as human beings and they have been able to acknowledge him as a human being and not merely as the monolithic "teacher." The gift at the end with the tag of "To Sir, with Love" indicates that Braithwaite has come so very far in his struggle. The fundamental incident is this in terms of it marking the structural development of the plot as well as the growth of his own characterization. In this, the novel centers on how Braithwaite's professional growth and personal embrace of the teaching profession become critical elements and significant incidents in the novel.