An example of a literary device is the metaphor and symbolism of killing a mockingbird.
Part Two starts at Chapter 12. It covers the trial and the incidents following it.
One of the literary devices used in these chapters is symbolism. People can be symbols, and the main symbols in these chapters are Tom Robinson and Boo Radley. They are symbols throughout the entire story, but these chapters weave them together.
Let me define the literary devices of symbol, metaphor, and simile first. A symbol is when an object or person is one thing that stands for a bigger idea. A metaphor is a direct comparison, saying something is something else, such as saying a person is a mockingbird. A simile is when something is compared to something else, using like or as ("like shootin' a mockingbird"). In this case, people are the mockingbirds.
Earlier in the book, when Scout and Jem are given guns, they are told not to shoot at birds.
Shoot all the bluejays you want, if you can hit 'em, but remember it's a sin to kill a mockingbird. (Ch. 10)
Scout asks Miss Maudie why Atticus says this, since he never says it’s a sin to do anything. She explains that mockingbirds are harmless. They “don't do one thing but make music for us to enjoy.” They aren’t a nuisance like other birds, so you shouldn’t target them. They should target the bluejays instead.
This is significant, because Tom Robinson is our symbolic mockingbird. He doesn’t do anything but help Mayella Ewell. He feels sorry for her, because she is alone in that house with all of those children. He cuts up furniture for her and notices that she is lonely.
"Why were you so anxious to do that woman's chores?"
Tom Robinson hesitated, searching for an answer. "Looked like she didn't have nobody to help her, like I says-"
"With Mr. Ewell and seven children on the place, boy?"
"Well, I says it looked like they never help her none-" (Ch. 19)
He is a good person, like the mockingbird. Yet he is targeted by society because he is black. Mr. Gilmer makes a big deal about how he must be helping her in order to get something in return. He can’t just be a decent person. His cross-examination is dripping with racism, and he does not treat Tom Robinson with respect.
Tom is literally the mockingbird who is shot. When he is convicted (symbolically shot), he does not feel he can be acquitted. He decides to commit what is essentially suicide by cop, and is actually shot, climbing the fence. He knew he could never get away, since he only had one good arm.
The other mockingbird in the story is Boo Radley. He is a victim of society in a different way. He is white, so it is not an issue of race. He is a recluse. As a child, he was sort of wild. He made some bad choices, so his super-religious parents locked him up in his house and never let him out. There he has remained for his entire life. Now he is the town ghost, and his brother basically keeps him prisoner.
When Arthur “Boo” Radley tries to initiate a friendship with the children in the neighborhood by leaving them presents in a tree, Nathan Radley cements the hole.
"Mr. Radley, ah- did you put cement in that hole in that tree down yonder?"
"Yes," he said. "I filled it up."
"Why'd you do it, sir?"
"Tree's dying. You plug 'em with cement when they're sick. You ought to know that, Jem." (Ch. 7)
The tree is not really dying. It is just a way of preventing Scout and Jem from having any communication with Boo. Now, you can argue that it is odd for a grown man to “play” with children. You have to remember though that Boo is basically a child himself. He is just a shy, childlike man who has been denied any connection with the outside world by his family and circumstances. The cement in the hole made Scout cry. I can only imagine how Boo felt.
When Boo sees Bob Ewell attack Scout and Jem on Halloween night, he does not stop to think about his own safety. He is a slight man, and he cannot be very strong (he spends most of his life indoors). Yet he takes Mr. Ewell on and kills him. He has shown time and time again that he will look out for and protect Scout and Jem, from sewing Jem’s pants so that he won’t get into trouble, to putting the blanket on Scout’s shoulders so she wouldn’t catch a cold during the fire at Miss Maudie’s house. That night with Mr. Ewell, he literally saves their lives.
Atticus and Heck Tate decide that they do not want to tell anyone what Boo Radley did. He does not want any notoriety. He is a private man, and if everyone knew, he would not know how to handle it. When they explain it to Scout, she completely gets it.
"Scout," he said, "Mr. Ewell fell on his knife. Can you possibly understand?" …
"Yes sir, I understand," I reassured him. "Mr. Tate was right."
Atticus disengaged himself and looked at me. "What do you mean?"
"Well, it'd be sort of like shootin' a mockingbird, wouldn't it?" (Ch. 30)
Scout has really matured. She has gone from thinking that Boo Radley is a scary monster to understanding that he is a sensitive man who is their friend. In this chapter, she gently takes his hand and walks him home with all of the maturity and politeness of a Southern belle.