What did the trial mean to Jem that it did not mean to Scout in To Kill A Mockingbird? Jem reacts furiously to Scout's question about Miss Gates'...

is older,
so he understands more about the trial thandoes.  At Jems age, he is very interested in
justice.  He is feeling more adult, and he wants to experience things as an adult.  He is
convinced thatis going to win the trial.

When Atticus tells Jem be thinks the
jury wont deliberate long, Jems response is telling.

"You think they'll acquit him that fast?" asked Jem. (ch 21)

Jem saw the trial.  He understood that Atticus was proving that the
crime was not even committed and that Tom Robinson was crippled and could not have committed it
any way.  He assumes that this means that Tom will be acquitted. 

Scout does
not really know what to expect.  She is younger, and understands less of the process than Jem. 
She realizes that Atticus has proven Toms innocence, but does not know enough to expect him to
be acquitted.

The verdict is a harsh blow for Jem.  He expected the world to
be fair, and he finds out it isnt.

Jem is also at an age when he really looks
up to and admires Atticus.  He even says he wants to be a lawyer.  He sees the trial as law
school.  He thinks that lawyers work in a world of fairness.  The guilty verdict squashes those
dreams too.

It was Jem's turn to cry. His face was
streaked with angry tears as we made our way through the cheerful crowd. "It ain't
right," he muttered, all the way to the corner of the square where we found Atticus
waiting.  (ch 22)

Jem gets a harsh lesson in how the
world really works.  Atticus agrees with him that it is not right.  He says he will try for an
acquittal, but he is not confident.  He knows that racism is an insurmountable battle.  This is
the lesson that Jem is learning, but Scout only understands that Jem is
upset.