In Chapter 27 of To Kill a Mockingbird, what three incidents concerning the Ewells occur and what is learned about Bob Ewell?

Scout lists three things that happened: first, Ewell "acquired and lost a job in a mater of days; second, Judge Taylor suspects someone is poking around his yard in the night, with the implication that it is Ewell, and therefore pulls out a shotgun and puts it in his lap; third, Ewell harrasses Tom's widow, causing her employer to come to her defense.  We learn from these incidents that Ewell seeks revenge from those that humiliated him in the trial.